August 2014, Questions 25 and 26
25. In the equation x2 + 10x + 24 = (x + a)(x + b), b is an integer. Find algebraically all possible values of b.
x2 + 10x + 24 factors into (x + 4)(x + 6), the order of the two binomials doesn't matter.
So the possible values of b are 4 and 6.
26. Rhonda deposited $3000 in an account in the Merrick National Bank, earning 4.2% interest, compounded annually. She made no deposits or withdrawals. Write an equation that can be used to find B, her account balance after t years.
The formula you need is B = P(1 + r)t
P = 3000, the principal, or starting amount
r = .042, which is 4.2% as a decimal
t is time. No specific value is given, so use the variable.
That makes the answer B = 3000(1.042)t
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