I need help solving this problem-1/5x – 8 = 4x + 3?

Question

I cant solve these problems. Could someone help me and show me the steps.
-1/5x – 8 = 4x + 3 (that is 1 over 5 just for your info)

2x + 7y = 35

5x – 2y = 15

Answer 1

OK

-1/5x – 8 = 4x + 3 ; firs thing to do is try to isolate x - multiply each side by 5

-x -40 =20x +15 ; now add x to both
-40 = 21x +15 ; subtract 15
-55 = 21x
-55/21= x

Check

-1/5(-55/21) - 8 = 4(-55/21) +3 ??
11/21 - 8 = -220/21 +3 ??
-7 10/21 = -157/21 ??
-157/21 = -157/21 YES!!!

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Now for this next set, I assume you want to use the two equations and two unknowns


2x + 7y = 35
5x – 2y = 15 ; ok - to solve this, mutiply the top by 5 and the bottom by 2

10x +35y = 175
10x - 4y = 30 ; now subtract the second from the first

39y = 145
y = 145/39

Substitute

5x - 2(145/39) =15
5x - 290/39 =15
5x = 15 + 290/39
x = 3 + 58/39
x = 175/39

Now check

2(175/39) + 7(145/39) = 35??
350/39 + 1015/39 = 35 ??:
1365/39 = 35??
35 = 35 YES!!

Answer 2

add 1/5x to both sides
-8=4x + 1/5x +3
subtract 3 from both sides
-8-3=4x+1/5x
-11=6/5x
mult both sides by 5
-55=6x
divide both sides by 6
-55/6=x


Solve for x or y? more info-

2x+7y=35 (for x)
-7y both sides
2x=35-7y
divide by 2
x=35-7y/2 (all over 2)

for y move x to the other side and divide by the coefficient of y

next problem is the same

Good luck!

Answer 3

- 1/5x - 8 = 4x + 3

Multiply both sides of the equation by 5

- 5(1/5x) - 5(8) = 4(4x) + 5(3)

- x - 40 = 20x + 15

Transpose x

- x - 40 + x = 20x + 15 + x

Collect like terms

- 40 = 21x + 15

Traspose 15

- 40 - 15 = 21x + 15 - 15

Collect like terms

- 55 = 21x

Divide both sides of the equation by 21

- 55 / 21 = 21x / 21

- 55/21 = x

- 2 13/21

- - - - - - - -s-

Answer 4

Dear note down the method. First you have make the two equations equal by multiplying with such a digit that either x or y values become equal.

Steps

2x + 7y = 35 ----------eq i
5x - 2y = 15 -----------eq ii

Mutiply eq i by 2 and multiply eq ii by 7 as multiplying or dividing any equation by same digit doesnt effect the equation as it acts the same on both sides

after multiplications

4x + 14y = 70 ---------------- eq iii
35x - 14y = 105 ---------------eq iv

by adding these two newly formed equations we get
4x +14y +5x -14y = 70+105 (14y gets cancelled with -14y)
39x = 175
x = 175/39 (or 4.49)

now put the value of x in any equation you will get the value of y
4(175/39) + 14y = 70

700/39 + 14y = 70 -----------eq v
dividing eq v it by 39 you get
39(700/39) +39(14y) = 39(70)
700 + 546y = 2730
546y = 2730 - 700
546y = 2030
y = 2030/546

Y = 1015/273 as it cant be cancelled more y = 3.71
so the result is (x = 4.49, y= 3.71)

put these values in any equation to check the result
4(4.48) + 14(3.71) = 70
17.92 + 52.08 = 70
70 = 70 so result checked

Answer 5

-1/5x – 8 = 4x + 3
Multiply the eq. by 5
– x – 40 = 20 x + 15
– x – 20 x = 15 + 40
– 21 x = 55
x = – 55/21

2x + 7y = 35 -----------eq1
5x – 2y = 15 ----------eq2
Multiply eq. 1 by 2 and eq 2 by 7
4x + 14 y = 70 -------------eq3
35 x – 14y = 105 ---------eq 4
Adding eq.3 and eq 4
39 x = 175
x = 175 /39
substitute value of x,
instead of that,
2x + 7y = 35 -----------eq1
5x – 2y = 15 ----------eq2
Multiply eq. 1 by 5 and eq 2 by 2
10x + 35 y = 175 -------------eq5
10 x – 4y = 30 ---------eq 6
Subtracting eq.6 from eq 5
7y = 145
y = 145/7

x = 175 /39 & y = 145/7

Answer 6

-1/5x-8=4x+3
-1/5x-4x=3+8
-21x/5 = 11
-21x=11*5
-21x = 55
x = 55/21