Solve 2a-(8a+1)-(a+2)=9

$$2 a - ( 8 a + 1 ) - ( a + 2 ) = 9$$

Solve for a

$$a = -\frac{12}{7} = -1\frac{5}{7} \approx -1.714285714$$

Steps for Solving Linear Equation

To find the opposite of 8a+1, find the opposite of each term.

$$2a-8a-1-\left(a+2\right)=9$$

Combine 2a and -8a to get -6a.

$$-6a-1-\left(a+2\right)=9$$

To find the opposite of a+2, find the opposite of each term.

$$-6a-1-a-2=9$$

Combine -6a and -a to get -7a.

$$-7a-1-2=9$$

Subtract 2 from -1 to get -3.

$$-7a-3=9$$

Add 3 to both sides.

$$-7a=9+3$$

Add 9 and 3 to get 12.

$$-7a=12$$

Divide both sides by -7.

$$a=\frac{12}{-7}$$

Fraction \frac{12}{-7} can be rewritten as -\frac{12}{7} by extracting the negative sign.

$$a=-\frac{12}{7}$$