Question

x+1 supra 4 =1 virgula 5

Answer 1

x+1 supra 4 = 15 supra 10.
x+1 = 4·15 supra 10
x+1 = 60 supra 10
x+1 = 6 
x= 6-1
x = 5

Answer 2

$\frac{x+1}{4} = 1, 5$  
$\frac{x+1}{4}= \frac{15}{10}$   rezulta ca
x+1 × 10=4 × 15
x+1 × 10=60
x+1=60 : 10
x+1=6
x=6 - 1
x=5