Answer:
5. Katelyn worked 11 hours at the grocery store.
6. 5pounds of steak
Step-by-step explanation:
5. let x hrs be the no. of hours Katelyn worked at the grocery store.
amnt of money she earnt = 9x + (15-x)×15
= 9x -15x + 225
= -6x + 225
-6x + 225 = 159
6x = 225-159
6x= 66
x= 11
Katelyn worked 11 hours at the grocery store.
6. Let x be the pounds of steak he purchased.
total paid= 13.50x + (8-x)×3.25
= 13.50x -3.25x +26
= 10.25x +26
10.25x+ 26=77.25
10.25x = 77.25-26
10.25x= 51.25
x=5
try using the same method for qn 7 too
Answer:
f(-1) = 81
Step-by-step explanation:
Given the function, , we can find f(-1) by plugging in -1 into the function:
<em>f </em>(-1) = 81
1/2 times base times height
12 times 6 equal 72
72 divides by a half equals 36
We use the fact that if x+y+z = 0, then x³+y³+ z³ = 3 x y z.<span>
(x</span>²-y²) + (y²-z²) + (z²-x²) = 0<span>
also: (x-y) + (y-z)+ (z-x) = 0
we assume that: x </span>≠y ≠ z.
<span>
hence,
(x²-y²)³ + (y²-z²)³ + (z²-x²)³ ÷ (x-y)³ + (y-z)³ + (z-x)³
= 3 (x</span>²-y²) (y²-z²) (z²-x²) ÷ [3 (x-y) (y-z) (z-x)]
<span>= (x+y) (y+z) (z+x)</span>