Step 1. Simplify
7x^2 - 8x - 4 - 2x^2 + 3x + 5 + 5x^2 - 10x - 8
Step 2. Collect like terms
(7x^2 - 2x^2 + 5x^2) + (-8x + 3x - 10x) + (-4 + 5 - 8)
Step 3. Simplify
10x^2 - 15x - 7
Y = kx
when y= 12, x=3
12 = 3k
k = 12/3
k = 4
y = 4x
when x= 15
y = 4(15)
y = 60
My sister knows that I’ll go get her
Distribute
x-12x+30=-x-4
Combine like terms
-11x+30=-x-4
Add x to both sides
-10x+30= -4
Subtract 30 from both sides
-10x=-34
Divide both sides by -10
x=3.4
Final answer: x=3.4
