5x+2y=7. 4x+y=8 systems of equations substitution method

x=3 and y=−4

Step-by-step explanation:

Solve4x+y=8for y:

4x+y=8

4x+y+−4x=8+−4x(Add -4x to both sides)

y=−4x+8

Step: Substitute−4x+8 for y in 5x+2y=7:

5x+2y=7

5x+2(−4x+8)=7

−3x+16=7(Simplify both sides of the equation)

−3x+16+−16=7+−16(Add -16 to both sides)

−3x=−9

-3x/-3=-9/-3

(Divide both sides by -3)

Step 2: Substitute 3 for x in y=−4x+8:

y=−4x+8

y=(−4)(3)+8

y=−4(Simplify both sides of the equation)

answer: 177/8

step-by-step explanation:

answer:   b

step-by-step explanation:

x2 = 16

x can not be a negative number because 16 is positive

the only answer would be positive 8