Marvin wrote the following clues to describe a multiplication sentence the product is close in value to 10 both factors are decimal numbers the product has three decimal places one factor is greater than 1 the other factor is less than 1
using the given formula for area : a = bh
(a) given b = 8 and h = 5, then
a = × 8 × 5 = × 40 = 20 units²
(b) given a = 18 and b = 4, then
18 = × 4 × h = 2h ( divide both sides by 2 )
h = 9 units
(c) given a = 14 and h = 7, then
14 = × 7 × b = 3.5b ( divide both sides by 3.5 )
b = 4 units
the slope is found by using the formula
the points are (1,4) and (1,-3)
m = (y2-y1)/(x2-x1)
= (-3-4)/ (1-1)
= -7/ 0
when we divide by 0 the answer is undefined
the correct answer is that a rose bush costs $10 and a shrub costs $4
to solve this, start by writing equations for what each spent. use x for the cost of a rose bush and y for the cost of a shrub. below would be the equations for each.
rob: 8x + 5y = 100
amy: 8x + 8y = 112
now to find the cost, we multiply rob's equation by -1 and add them together. this will get x to cancel and allow us to solve for y.
-8x - 5y = -100
8x + 8y = 112
3y = 12
y = 4
so we know the cost of a shrub is $4. now we can plug that in to either of the original equations and solve for the rose bush cost.
8x + 5y = 100
8x + 5(4) = 100
8x + 20 = 100
8x = 80
x = 10
which means that a rose bush costs $10.