I need help ...kinda sad I know?

Question

1. (2x^2+5x-1)-(8x-3)
2. X axis is? 3x+2y= -10 and x-4y=6
3. Solve x^2+10=7X

Please help

It isn't homework. Im trying to solve these problems out of the book for practice but I need a little help in doing that.

Answer 1

1. 2x^2-3x+2 (5x-8x = -3x, and -1 - (-3) = -1 + 3 = 2)

2. Are you looking for where these lines cross the x axis? If so, y=0, and:
2x+2*0=-10
2x+0=-10
2x=-10
x=-5 for the first one, and

x-4*0=6
x-0=6
x=6 for the second one.

3. x^2+10=7x
x^2-7x+10=0

There are many options here. If you know the quadratic formula, go for it. I'll complete the square in this example:

x^2-7x=-10
x^2-7x+49/4=-10+49/4
(x-7/2)(x-7/2)=-40/4+49/4
(x-7/2)^2+(-40+49)/4
(x-7/2)^2=9/4
x-7/2=3/2 (take the square root of both sides)
x=3/2+7/2
x=(3+7)/2
x=10/2
x=5.

Answer 2

I'm not going to do your homework!