Find the value of p if (frac{1}{4})p + 3q = 10 and 2p – q = 7
-
A.
4 -
B.
3 -
C.
-3 -
D.
-4
Correct Answer: Option A
Explanation
(frac{1}{4})p + 3p = 10…(1)
2p – (frac{1}{3})q = 7…(2)
Multiply equation (2) by 3 to clear fraction
3 x 2p – 3 x (frac{1}{3})q = 3 x 7
6p – q = 21
6p – 21 = q….(3)
substituting 6p – 21 for q in (1)
(frac{1}{4})p + 3(6p – 21) = 10…(4)
Multiply equation (4) by 4 to clear fraction
4 x (frac{1}{4})p + 4 x 3(6p – 21) = 4 x 10
p + 12(6p – 21) = 40
p + 72p – 252
73p = 292
p = (frac{292}{73})
= 4