Answer:
y = - 10
Step-by-step explanation:
Given that y varies directly with x then the equation relating them is
y = kx ← k is the constant of variation
To find k use the condition y = 2 when x = - 4, that is
2 = - 4k ( divide both sides by - 4 )
= k, that is
k = -
y = - x ← equation of variation
When x = 20, then
y = - × 20 = - 10
Answer:
Solution: x = 6
Step-by-step explanation:
Given equation is:
In order to solve the equation both sides will be squared
Verifying the solution
Step-by-step explanation:
angle EAB = 2x too, due to the laws of the same and mirrored angles when a line crosses 2 parallel lines.
the angle ABE is 180 - 6x, due to the fact that all angles around a single point on one side of a line ad up to 180 degrees.
similarly, the angle AEB is 180 - 4x.
and then we know the sum of all angles in a triangle is airways 180 degrees.
so,
180 = 2x + 180 - 4x + 180 - 6x
0 = 180 - 8x
8x = 180
x = 22.5
They need to buy six because they will end up with fifty four.
(they cant buy five because they would end up with forty five and that wouldnt be enough)
