Question

For what value of a&b the linear equation 2x+y-5=0; (a+b)x+(a-2b)y-15=0, has infinte soloution

Answer 1

from the question there are there are two equation first is a+b=6 and second a-2b= 3 now solve it and value of x is 9 and B is 3

Answer 2

Lines which have infinite solutions have equation
$\frac{a1}{a2} = \frac{b1}{b2} = \frac{c1}{c2} \\ \frac{2}{a + b} = \frac{1}{ a- 2b} = \frac{5}{15} \\ \frac{2}{ a+ b} = \frac{5}{15} \\ 30 = 5(a + b) \\ a + b = 6 \: \: \: \: \: (1) \\ \frac{1}{ a- 2b} = \frac{5}{15} \\ \frac{15}{5} = a- 2b \\ a - 2b = 3 \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: (2) \\ from \: (1) \\ a \: = 6 - b \\ (6 - b) - 2b = 3 \\ 6 - 3b = 3 \\ b = 1 \\ a = 6 - 1 = 5$
value of a is 5 and b is 1