Question

решить (1,8+х)*21=71,4

Answer 1

1.8*21+21x=71.4
37.8+21x=71.4
21x=71.4-37.8=33.6
x=33.6/21=1.6

Answer 2

(1,8+x)•22=71,4
37,8+22x=71,4
21x=-37,8+71,4
21x=33,6
x=33,6:21
x=1,6