QUESTION 16
The correct answer is 3. The solution to the given equation can
be found by factoring the quadratic expression.
The factors can be
determined by finding two numbers with a sum of 1 and a product
of −12. The two numbers that meet these constraints are 4 and –3.
Therefore, the given equation can be rewritten as (
x + 4)(
x − 3) = 0. It
follows that the
solutions to the equation are x = −4 or
x = 3. Since it
is given that
a > 0,
a must equal 3.
QUESTION 17
The correct answer is 32. The sum
of the given expressions is
(−2
x
2
+
x + 31) + (3
x
2
+ 7
x − 8). Combining like terms yields
x
2
+ 8
x + 23.
Based on the form of the given equation,
a = 1,
b = 8, and
c = 23.
Therefore,
a +
b +
c = 32.
Alternate approach: Because
a +
b +
c is the value of
ax
2
+
bx +
c when
x = 1, it is possible to first make that substitution
into each polynomial
before adding them. When
x = 1, the first polynomial is equal to
−2 + 1 + 31 = 30 and the second polynomial is equal to 3 + 7 − 8 = 2.
The sum of 30 and 2 is 32.
QUESTION 18
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