Answer:
x=√65 and x=-√65
Step-by-step explanation:
Givn the expression 2x^2 - 9 = 121
Add 9 to both sides
2x^2 - 9 + 9 = 121 + 9
2x^2 = 130
Divide both sides b 2
2x^2/2 = 130/2
x^2 = 65
x = ±√65
x=√65 and x=-√65
Answer:
x=2
Step-by-step explanation:
Your sister is 24. Your brother is 20. You are 15. Therefore, your sister will be 48 years old. I’m 87% sure I did this right. Lol, good luck.
Its A i believe :) (Hope you get it right!)
It will take exactly 4 years for these trees to be the same height
Step-by-step explanation:
A gardener is planting two types of trees:
- Type A is 3 feet tall and grows at a rate of 7 inches per year
- Type B is 5 feet tall and grows at a rate of 1 inches per year
We need to find in how many years it will take for these trees to be the
same height
Assume that it will take x years for these trees to be the same height
The height of a tree = initial height + rate of grow × number of years
Type A:
∵ The initial height = 3 feet
∵ 1 foot = 12 inches
∴ The initial height = 3 × 12 = 36 inches
∵ The rate of grows = 7 inches per year
∵ The number of year = x
∴
= 36 + (7) x
∴
= 36 + 7 x
Type B:
∵ The initial height = 5 feet
∴ The initial height = 5 × 12 = 60 inches
∵ The rate of grows = 1 inches per year
∵ The number of year = x
∴
= 60 + (1) x
∴
= 60 + x
Equate
and 
∴ 36 + 7 x = 60 + x
- Subtract x from both sides
∴ 36 + 6 x = 60
- Subtract 36 from both sides
∴ 6 x = 24
- Divide both sides by 6
∴ x = 4
∴ The two trees will be in the same height in 4 years
It will take exactly 4 years for these trees to be the same height
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