If a=3x^2+5x−6 and b=−2x−6x+7, then what is a-b

A=3x^2+5x-6

B=-2x^2-6x+7

A-B=(3x^2+5x-6)-(-2x^2-6x+7)

remove parentheses

A-B=3x^2+5x-6+2x^2+6x-7

combine like terms

A-B=5x^2+11x-13

constant acceleration- a

constant velocity- c

no velocity or acceleration- b

explanation:

for body moving with a constant acceleration, the rate of change of displacement changes over time. this is proven by the increasing gradient of the curve (a) against time.

a body that is moving at constant velocity covers equal distances over equal periods of time, thus the straight line with a constant gradient c.

a stationary body   covers no displacement as time elapses. thus the flat line with   zero gradient.