Answer:
m = -3 and b = 5
Step-by-step explanation:
y = -3x + 5
.......
16+5x =8x-5
Reorder the terms
16+5x = -5+8x
Solving for variable for x
Move all terms containing x to the left, all other terms to the right.
Add -8x to each side of the equation.
16+ -3x = -5 + 8x + -8x
Combine like terms: 5x + -8x=-3x
16+-3x = -5 + 8x + -8x
Combine like terms: 8x + -8x = 0
16+-3x = -5 + 0
16+ -3x = -5
Add -16 to each side of the equation
16+-16 + -3x = -5 + 16
Combine like terms: 16+ -16 = 0
0 + -3x =-5 + -16
-3x = -5 + -16
combine like terms: -5 + -16 = -21
-3x = -21
Divide each side by -3
x=7
Answer:
27 hours
Step-by-step explanation:
Just do the reverse. 65-11 = 54. 54 / 2 = 27.
Lets be a price of the calculator - $ a
then , after using the coupon, you need to pay $(a-18)
and after using 15% discount , you need to pay (1-0.15)a=0.85a
then, if
(a-18) will be more than 0.85a, you should prefer 0.15 % discount, because it will be cheaper,
a-18> 0.85a
a-0.85a>18
0.15a > 18
a>120, that means that if the price of the calculator more than $120, 15% discount is better,
but if the price of the calculator is less than $120, you should choose $ 18 coupon.
for example, we have the price of the calculator $100
100-18=82,
100*0.85 =85, coupon is better.
If the price of the calculator $200
200-18=182,
200*0.85=170, so 15% discount is better
if price of the calculator is $120,
120-18=102
120*0.85=102,
it will not matter, what you are going to use, because you are going to pay the same amount of money
