Answer:
Step-by-step explanation:
7). (x + 3)(x + 7)
= x(x + 7) + 3(x + 7)
= x² + 7x + 3x + 21
= x² + 10x + 21
8). (4x + 2)(x - 2)
= 4x(x - 2) + 2(x - 2)
= 4x² - 8x + 2x - 4
= 4x² - 6x - 4
9). (3x + 2)(2x + 5)
= 3x(2x + 5) + 2(2x + 5)
= 6x² + 15x + 4x + 10
= 6x² + 19x + 10
10). (x² - 6)(x - 4)
= x²(x - 4) - 6(x - 4)
= x³ - 4x² - 6x + 24
11). (x² + 9)(x - 3)
= x²(x - 3) + 9(x - 3)
= x³ - 3x² + 9x - 27
12). (4x²- 4)(2x + 1)
= 4x²(2x + 1) - 4(2x + 1)
= 8x³ + 4x² - 8x - 4
Answer:
how do i use this site im new
Step-by-step explanation:
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
