Question

If a + b = 10, b - a = 12, then what is the value of 2a + b ?​

Answer 1

Given equations,

$a+b=10$ _____(1)

$b-a=12$______(2)

Add equation (1) and (2)

$a+b+b-a=10+12$

$2b=22\\b=11$

Substitute $b=11$ in equation (1)

$a+b=10\\a+11=10\\a=10-11\\a=-1$

According to the question

$2a+b=?$

Substitute $a$ and $b$ values in above equation

$2a+b=2\times-1+11\\2a+b=-2+11\\2a+b=9$

Therefore, The value of $2a+b$ is $9$.

Answer 2

Answer:

$9$

Step-by-step explanation:

Given equations

• $a+b=10$ and $b-a=12$

• We need to find the value of $2a+b$

• On adding the given two equations, we get

$a+b+b-a=10+12$

$\Rightarrow 2b=22$

$\Rightarrow b=11$

• On substituting the value of $b$ in $a+b=10$, we get

$a+11=10$

$\Rightarrow a=-1$

• Now, the value of $2a+b=2(-1)+11=-2+11=9$

Hence, the value of $2a+b=9$.