hi
a ( b +c) = a*b +a*c
here a = -3
b = -4x
c = +5
so :
-3 ( -4x +5) = -3*-4x + -3* 5
= -12x + (-15)
= -12x -15
as I cannot add -12x and -15 ( they are two differents sort of figures )
so it's done
45x +40(x+0.5) =270
45x +40x +20 =270
85x = 250
x = 250/85 = 2.94
45 * 2.94 = 132.3 miles
40*(2.94 +0.5) = 40*3.44 = 137.6
2.94 hours
There are several ways, but the general format follows f(x) = ax2 + bx + c f(x) = ax² + bx + c, where A, B, and C are non-zero numbers. Another way of finding a quadratic equation is examining the graph of it, you'll notice a "U" shape called a parabola, which come in many shapes but they all retain a "U"-like curve.
