Question

9) If a + 2b = 5, and ab=2, find a + 4b.​

Answer 1

Answer:

a = 1, 4

b = 2, 1/2

These are the values of a and b.

Answer 2

Step-by-step explanation:

$\huge\underline{\underline{\sf ANSWER}} \\ a + 2b = 5 .......(1)\\ ab = 2 \\ a = \frac{b}{2}......(2) \\ put \: (2) \: in \: (1) \\ \frac{2}{b} + 2b = 5 \\ 2 + 2 {b}^{2} - 5b = 0 \\ b = 2 \: \: \: or \: \: \: b = \frac{1}{2} \\ \\ \\ if \: b = 2 = > \\ ab = 2 \\ 2(a) = 2 \\ a = 1 \\ \\ if \: b = \frac{1}{2} \\ ab = 2 \\ a( \frac{1}{2} ) = 2 \\ a = 4$