Question

Which equation has a slope of -1 and an x-intercept of (2,0)

Answer 1

x + y = 2.

Explanation:

Using the standard form

y = mx + b

the equation is

y = -1x + b

Now as the x intercept is (2, 0), x = 2 when y = 0 so:

0 = -1(2) + b

2 = b

b = 2

so we have

y = -x + 2

y + x = 2.

Answer 2

A (x+y=2)

Explanation:

in order to see the slope value and to turn the equation into the slope-intercept form (y=mx+b). Basically we just solve for y and look at the coefficient of x. Then to see the value of the x-intercept we need to give y zero and then solve for x.

a) x+y=2

y=-x+2 (slope is -1)

when y=0 ; 0=-x+2 ; x=2 (x-int=2)

b) x-y=-2

y=x+2 (slope≠-1, it is +1 so this not the answer)

c) x+y=-2

y=-x-2 (slope is -1)

when y=0 ; 0=-x-2 ; x=-2 (x-int≠2 it is -2 so this not the answer)

d) x-y=2

y=x-2 (slope≠-1, it is +1 so this not the answer)

the answer is A (x+y=2)