I need help with these algebra problems, not just the answers but how to solve them?

Question

5-(-4)^2 / 9-4(-5+12)
7/8-x/64=0
-(40+72x)=56x-8(5-x)

Answer 1

5 -(- 4)² / 9 - 4(- 5 + 12)

5 - (16) / 9 + 20 - 48

5 - 16 / 29 - 48

- 11 / - 19

- - - - - - - - - - - - - -

7/8 - x/64 = 0

7/8 - x/64 + x/64 = 0 + x/64

7/8 = x/64

8x = 7(64)

8x = 448

8x/8 =448/64

x = 56

The answer is x = 56

- - - - - - - - - -

-(40 + 72x) = 56x - 8(5 - x)

- 40 - 72x = 56x - 40 + 8x

- 40 - 72x = 64x - 40

- 40 - 72x + 72x = 64x - 40 + 72x

- 40 = 136x - 40

- 40 + 40 = 136x - 40 + 40

0 = 136x

0/136 = 136x/ 136

0/136 = x

0 = x

--- - - - - -- -s-

Answer 2

The first 'equation' is lacking an equals sign so you just use the order of operations to arrive at a number:

Please Excuse My Dear Aunt Sally:
Parenthesis, then Exponents, then Multiplication, then division, then addition, then subtraction.
5-(-4)^2 / 9-4(-5+12) Parenthesis
= 5-(-4)^2 / 9-4(7) Exponents
= 5-16 / 9-4(7) Multiplication
= 5-16 / 9-28 Division
= 5 - (16/9) -28 Subtraction for the rest

Any time you are solving an equation, you want to isolate x (or the variable you are working with) by doing the 'opposite' operation.
7/8-x/64=0 move x term to other side with addition
7/8 = x/64 multiply each side by 64
7/8 * 64 = (x/64) * 64 simplify
56 = x

-(40+72x)=56x-8(5-x) Distribute negative sign on the left side
-40-72x=56x-8(5-x) Distribute -8 on right side
-40-72x = 56x-40+8x Combine x terms on right side
-40 -72x = 64x -40 Get the x's on the same side
-40 = 64x + 72x -40 Combine x terms
-40 = 136x -40 Get the constants on the same side
-40 + 40 = 136x Combine constants
0 = 136x Divide each side by 136
0/136 = 136x/136 Simplify
0 = x

Answer 3

Step 1: Reduce terms. This basically means that your first goal is to look at the problem and see if you can find any similarities in the numbers. Ex: 1x-2x reduced to (=) -1x or -x. Ex: (-5+12) = 7

Step 2: Make note of equating order. This means that roots (^), multiplication (*) and division (/) come first, then addition and subtraction.

Step 3: Remember that parens' ")" come first. So sove those first.

Step 4: Wrok through a problem in STEPS. That is, as you solve parts of the equation, get used to re-writing the euation below it.

Step 5: Isolate variables (like x). Remove them to one side if possible.

Step 6: Check answer with solved variable.

Let's try this one:
5-(-4)^2 / 9-4 (-5+12) 7/8-x/64=0

Step 1: parens and roots
5-(16) / 9-4 (7) 7/8 - x/64 = 0

Step 2: * and /
5 - 16/9 -4*7*7/8 - x/64 = 0

Step 3: Consoldate * and / and remove x/64 to one side
5 - 16/9 - 196/8 = x/64

Step 4: finish * and /
5 - 1.7778 - 24.5 = x/64

Step 5: consoldate and * both sides by 64
-21.2778 * 64 = x

Step 6: solve for x
x= -1361.7792

Step 7: Check x with origial equation:
5 - (-4)^2 / 9 - 4 (-5+12) 7 / 8 - x/64 =0
5 - 16/9 -4*7*7/8 - (-1361.7792)/64 = 0
5 - 1.7778 - 24.5 - (-21.2778) = 0
5 - 1.7778 - 24.5 + 21.2778 = 0
0 = 0

Step 8: Confirm 0 = 0

Hope this helps, and these steps can be use for almost any equation. There are many equations, with many solutions, which become much more difficult, however, there are STEPS that can be learned with them as well.

Stick with it...

Answer 4

Order of operations....


-(-4)^2 / 9-4(-5+12)

-(-4)^2 / 9 - 4(-5 + 12)
-(-4)^2 / 9 - 4(7)
-(16) / 9 - 4(7)
-16/9 - 28
-16/9 - 252/9 = -268/9 = -29 7/9


7/8-x/64=0

56/64 - x/64 = 0
(56-x)/64 = 0
56 - x = 0
56 = x

-(40+72x)=56x-8(5-x)

-40 - 72x = 56x - 40 + 8x
-40 - 72x = 64x - 40
-72x = 64x
0 = 64x + 72x
0 = 136x
0 = x

Answer 5

5-(-4)^2/9-4(-5+12)
5-16/9+20-48
-11/-19 =11/19
In the abovesolution, I have assumed you wanted everything above the / divided by everything below the slash.

7/8 -x/64=0
x/64=7/8
x= 64(7/8)=56

-(40 +72x) = 56x -8(5-x)
-40 -72x = 56x -40 +8x
-72x =56x+8x= 64x
136x=0
x=0