Question

Solve
2a + b =7
a + b =4​

Answer 1

so the value of a is 3 value of B is 1

Answer 2

➡a + b = 4 --- (i)

➡2a + b = 7 --- (ii)

Multiply the equation (i) by 2 and equation (ii) by 1

➡2a + 2b = 8 --- (iji)

➡2a + b = 7 --- (iv)

Subtract equation (iii) and (iv)

➡( 2a + 2b ) - ( 2a + b ) = 8 - 7

➡2a + 2b - 2a - b = 1

➡b = 1

Put the value of b = 1 in equation (iv)

➡2a + 1 = 7

➡2a = 6

➡a = 3