SOLUTION: I don't understand substitutions Trying to resolve: 7(x+3) - 2x(x+5)

SOLUTION: I don't understand substitutions Trying to resolve: 7(x+3) - 2x(x+5)

Algebra.Com

Question 498243: I don't understand substitutions
Trying to resolve: 7(x+3) - 2x(x+5)
Answer by deborabr(181) (Show Source): You can put this solution on YOUR website!
7(x+3) - 2x(x+5)
7x+21-2x^2-10x
-2x^2+7x-10x+21
-2x^2-3x+21 *(-1) to change the signal
2x^2+3x-21
RELATED QUESTIONS
my math teacher taught us how to do this but i don't understand (3,2), y = x + 5 (answered by josgarithmetic)

Quick question. 23-(x-7) Trying to understand how this is solved. I know the... (answered by josgarithmetic)

I don;t really understand how to get the answers to these problems, please help. f(x)=... (answered by solver91311)

Need to understand how to resolve this equation (3/2)x - (5/6) + x = (1/2)x + (2/3) (answered by josmiceli)

g(x)=6x+12 f(x)=2X+3 Question: 1. Find the (f o g) (x)+X^2 2. Set the... (answered by stanbon)

f(x)=3X+2 and g(x)=-2X+1 find g(f(-2)) I don't understand how to solve this... (answered by ikleyn)

how to resolve this 3(x-4)>15 28<4(5-2x) 3(2n+1)>4n+9 3n-10<7(2+n) (answered by rahman)

I don;t know how to solve this.... (answered by Fombitz,MathTherapy)

What would be the solution for x in the rational equation: x^2/(x-3) = (x+2)/(2x-5) (answered by josgarithmetic)