1)87100:(870+х)=100
870+x=87100:100
870+x=871
x=871-870
x=1
2)3*(0,2х-5)-4*(0,3-5)=10+0,4х
0.6x – 15 – 1.2 + 20 = 10 + 0.4x
0,6x – 0,4x = 10 – 20 + 1,2 + 15
0.2x = 6.2
x = 31
1)87100:(870+х)=100
870+x=87100:100
870+x=871
x=871-870
x=1
2)3*(0,2х-5)-4*(0,3-5)=10+0,4х
0.6x – 15 – 1.2 + 20 = 10 + 0.4x
0,6x – 0,4x = 10 – 20 + 1,2 + 15
0.2x = 6.2
x = 31