8x+15=7
answer: x= 1 hope this help
Answer:
30
Step-by-step explanation:
Simply it as follows:
1 + 39 = 40
2 + 38 = 40 etc
18 + 22 = 40
19 + 21 = 40
There are 19 of these plus 40 itself . . .therefore 20 of them
20 x 40 = 800
And finally the last number not used, 20
Therefore 800 + 20 = 820
Answer:
(2x - 9)(2x + 9)
Step-by-step explanation:
4x^2 - 81 = (2x - 9)(2x + 9)
$45.50
2 bags = $7
13 bags=?
7÷2=3.5
3.50=1 bag
$3.50 × 13 bags = $45.50 for 13 bags of Doritos