Algebra help?

Question

Bob invested $21,000, part at 18% and part at 8%. If the total interest at the end of the year is $1,980, how much did he invest at 18%?

2.Solve the system by addition.
–3x + 4y = –16
x – 2y = 12
3.Graph f(x) = 3x + 2.

4.Solve the following system of linear inequalities by graphing.
x – 2y less than equal to 4
x greater than equal to 4

Answer 1

for Q2

-3x + 4y = -16 ---------------------(1)
x - 2y = 12 ----------------------(2)

eq (2) * 2
2x - 4y = 24 ------------------(3)

eq (1) + (3)
-x = 8
x = -8

substitute x= -8 into eq (2)
-8 - 2y = 12
-2y = 20
y = -10


x= -8 , y= -10

sorry if i'm wrong

Answer 2

For increasing cubic binomials the final formulation is as follows: (a + b) ^ 3 = a^3 + 3*a^2*b^a million + 3*a^a million*b^2 + b^3 on your case, a is x and b is -y^5 So (x - y^5)^3 = x^3 + 3*x^2*(-y^5)^a million + 3*x^a million*(-y^5)^2 + (-y^5)^3 Simplified: =x^3 - 3x^2*y^5 + 3x*y^10 - y^15 :D

Answer 3

1. (.18x) * (.08(21000-x)) = 1980

2. multiply the second equation by 2, then add the 2 equations together
3. up 2, draw a line with slope 3
4. graph the two lines, then find the inequality.

Answer 4

1.x*0.18+(27000-x)*0.08)=1950
18x+1960-8x=195000
10x=195000-1960=193040
x=19304
he invested 19304@18% and
1696 @8%

2.-3x+4y=-16
3x-6y=36
adding
-2y=20
y=-10
substituting
x=-8

3.

4.

graphing i will not be able to do for you

Answer 5

I am taking college algebra when I am having troubles I look on the web. You can find sites that can help you. Some have helped me.

Answer 6

Sorry- not a clue how 2 do algebra!!
I'm just bored!!!!!!!

Answer 7

you should not cheat on your homework. you will only fail later.