What’s the value of x in both a & b?

a) 7

b) 2 2/7

Step-by-step explanation:

A) 2/7=2/x

x=7

B) 2/7=x/8

cross multiply

16=7x

x=16/7, or 2 2/7, or 2.2857

assuming you mean addition: addition and subtraction are reverse operations.

step-by-step explanation:

5=812a+9+3

step 1: simplify both sides of the equation.

5=812a+9+3

5=(812a)+(9+3)(combine like terms)

5=812a+12

5=812a+12

step 2: flip the equation.

812a+12=5

step 3: subtract 12 from both sides.

812a+12−12=5−12

812a=−7

step 4: divide both sides by 812.

812a /812 = -7/812

a= -1/116

so the answer is

a=   -1/116