1.3×7=25.1-8x
9.1=25.1-8x
8x=25.1-9.1
8x=16
x=16÷8
x=2
(25+2x)×4=340
25+2x=340÷4
25+2x=85
2x=85-25
2x=60
x=60/2
x=30