X = pencils, y = pens
8x + 6y = 8.50
4x + 4y = 5.....multiply by -2
----------------
8x + 6y = 8.50
-8x - 8y = -10 (result of multiplying by -2)
-----------------add
-2y = - 1.50
y = -1.50 / -2
y = 0.75 <=== pens cost 0.75
4x + 4y = 5
4x + 4(0.75) = 5
4x + 3 = 5
4x = 5 - 3
4x = 2
x = 2/4
x = 0.50 <== pencils cost 0.50
Answer:
Step-by-step explanation:
100,000 doubles to 200,000 in 80 years then 400,000 in 80 more years
Answer:
Step-by-step explanation:
the surface area = area of the 4 faces+ area of the 2 bases
4 *(15*8) + 2*( 8*6) = 480+96 = 576 cm²
if the length of the faces tripled, the two bases remain unchanged because the prism just gets taller on the same bases.
Answer:
(g°f)x =16 when x = 5
Step-by-step explanation:
It might be easier to understand if you wrote this the other acceptable way.
g(x) = x^4
f(x) = 2x - 8
g(f(x)) means that in g(x) wherever you see and x you put f(x)
g(f(x)) = (f(x) ) ^ 4 Now put in the general value for f(x)
g(2x - 8) = (2x - 8)^4
You really don't want to expand this (although it would give you the right answer eventually).
g(2*5 - 8) = (2 * 5 - 8)^4
g(2*5 - 8) = (10 - 8)^4
g(2*5 - 8) = 2^4
Answer 16