Twice one number plus a second number is 42 and the first number is 4 more than 3 times the second

x = 130/7, y = 34/7

Step-by-step explanation:

Let x = the first number

and y = the second number

Then

                                                          (1) 2x +   y = 42

                                                          (2)          x = 3y + 4

Subtract 3y from each side of (2)    (3)  x  - 3y = 4

Multiply Equation (3) by 2                (4) 2x - 6y = 8

Subtract (4) from (1)                                       7y = 34

Divide each side by 7                      (5)         y = 34/7

Substitute (5) into (1)                         2x + 34/7 = 42

Subtract 34/7 from each side                     2x = 42 - 34/7

Simplify                                                        2x = 260/7

Divide each side by 2                                   x = 130/7

x = 130/7, y = 34/7

Check:

(1) 2(130/7) + 34/7 = 42     (2) 130/7 = 3(34/7) +  4

     260/7   + 34/7 = 42          130/7 =  102 /7  + 28/7

                  294/7 = 42          130/7 =   130/7

                       42 = 42

the solution is the point

step-by-step explanation:

we have

> equation a

> equation b

adds equation a and equation b

substitute the value of x in equation b to find the value of y

the solution is the point