The product of a number and -7 amounts to seven times the sum of that number and 20. Find the number.

-10

Step-by-step explanation:

If you put it in an equation it would be -7x=7(x+20). You would then -7x to both sides to get -14x=140. Just divide -14 on both sides to isolate x. This equates to -10. If you put -10 back into the equation then it says that 70 is 7 times larger than 10. Which it is.

x = -3

y = -18

step-by-step explanation:

to solve by substitution, substitute one variable and solve for the other. then substitute again to find the remaining variable.

x-1/3(3x-9) = -3 since y=3x-9 substittute y.

x-1/3(3x-9)=-3

x + x +3 = -3

2x+3=-3

2x+3-3= -3-3

2x=-6

x=-3

substitute again into y=3x-9

y=3(-3)-9

y=-9-9

y=-18