Question

Given: y= 2x + 1 and - 4x + y = 9,
solve the system by substitution

Answer 1

Answer:

x=-4     y=-7

Step-by-step explanation:

-4x+y=9     get y alone

add 4x both sides

y=4x+9

insert into y=2x+1

2x+1=4x+9

subtract 1 both sides

2x=4x+8

subtract 4x both sides

-2x=8

divide by -2

x=-4

y=2x+1

y=2(-4)+1

y=-8+1

y=-7

check

-4(-4)+(-7)=9

-16+(-7)=9

9=9

x=-4

y=-7

gl