X + 3y = 1 −3x − 3y = −15 solved by substitution please show work so i can understand

x=7

y= -2

Step-by-step explanation:

x+3y=1 (1)

−3x−3y=−15 (2)

Solve Equation (1) for x

x=1−3y

Substitute x=1−3y in equation (2)

−3(1−3y)−3y=−15

−3+9y−3y=−15

−3+6y=−15

6y=−15+3=−12

y=−12/6=−2

y=−2

Substitute y=−2 in equation (1)

x+3(−2)=1

x−6=1

x=1+6=7

x=7

ok thats very interesting

answer: -10

step-by-step explanation:

s(t) = 1 - 10t

s(x) = 1 - 10x

s(x + h) = 1 - 10(x + h)

            = 1 - 10x - 10h

s(x + h) - s(x) = 1 - 10x - 10h - (1 - 10x)

                      = 1 - 10x - 10h - 1 + 10x

                      = -10h

= -10