Just the first one, r is 4x+2, and h is 5x+4, plug them into the formula pls
The zero product property tells us that if we have
xy=0, then we can assume that x and y both equal 0
so
(4k+5)(k+7)=0
we can assume that 4k+5=0 and k+7=0
so
4k+5=0
minus 5 both sides
4k=-5
divide both sides by 4
k=-5/4
k+7=0
minus 7 both sides
k=-7
k=-5/4 or -7
The sum of 14 and a number is 14+x
we know that this equals 17, so: 14+x=17.
Let's substract 14 from both sides:
x=17-14
x=3
so the number is 3.