What does is mean to be a solution of two linear equations​

On the way home from visiting his family, vincent’s plane cruised at an altitude of 3.2 × 104 feet. he had heard that a man named felix baumgartner skydived from an altitude of 1.28 × 105 feet. vincent wants to know how much higher felix went on his skydiving trip. question 1 you have already seen how adding numbers works in either scientific notation or standard notation. but can you subtract numbers in scientific notation and get the same results as subtracting in standard notation? to find out, first solve vincent’s problem in standard notation. part a write the cruising altitude of vincent’s plane in standard notation.

Solve the equation x/4 - 5= -8 -27 -12 -7 12

Can some one explain how to slove specifically, what is the value of x? 0.9(x+1.4)-2.3+0.1x=1.6 enter the answer as a decimal in the box. x= ?