Answer:
(6-√21, 6+√21)
Step-by-step explanation:
x^2 - 12x = -15
(x - 6)^2 - 36 = -15
(x - 6)^2 = 21
x - 6 = ± √21
x = 6 ± √21
Answer:
One number is 17 and the other is 85.
Step-by-step explanation:
Let the numbers be m and n. Let m = (1/5)n. Note that m+n = 18.
Substituting (1/5)n for m in the 2nd equation, we get (1/5)n + (5/5)n = 18. Multiplying all three terms by 5 to remove fractions, we get n + 5 = 90, so that n = 85. m is (1/5) of 85, or m = 17.
Data:
Apples = 28
Oranges = 20
Pears = 12
<span>What is the ratio of apples to the total pieces of fruit?
Solving:
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Let's call the younger student's age A and the older student's age B. The teacher's age will be T.
B = 2A
T = 5B
T+5 = 5(A+5)
Simplify the last equation.
T+5 = 5A+25
T = 5A+20
Now we have two equations solved for T, so we can set them equal to each other.
5B = 5A + 20
We can plug 2A in for B
5(2A) = 5A + 20
10A = 5A + 20
5A = 20
A = 4
To find T, we plug 4 in for A in T = 5A + 20
T = 5(4) + 20
T = 40
The answer is 40 years old.
