WAEC - Mathematics (2019 - No. 16)
If 3p = 4q and 9p = 8q - 12, find the value of pq.
12
7
-7
-12
คำอธิบาย
9p = 8q - 12
9p = 2(4q) - 12
9p = 2(3q) - 12
9p = 6p - 12
3p = -12
p = -4
\(\frac{3 \times -4}{4} = \frac{4q}{4}\)
q = 13
pq = -3 x -4
= 12
9p = 8q - 12
9p = 2(4q) - 12
9p = 2(3q) - 12
9p = 6p - 12
3p = -12
p = -4
\(\frac{3 \times -4}{4} = \frac{4q}{4}\)
q = 13
pq = -3 x -4
= 12