Question

решить уравнения а*20=85-25 40+15+х=65 х/15=30/6 90-36+х=61

Answer 1

$20a = 85 - 25 \\ 20a = 60 \\ a = \frac{60}{20} \\ a = 3$

$40 + 15 + x = 65 \\ 55 + x = 65 \\ x = 65 - 55 \\ x = 10$

$\frac{x}{15} = \frac{30}{6} \\ 6x = 30 \times 15 \\ 6x = 450 \\ x = \frac{450}{6} \\ x = 75$

$90 - 36 + x = 61 \\ 54 + x = 61 \\ x = 61 - 54 \\ x = 7$

Answer 2

20a=60 55+x=65 X/15=5 54+x=61
a=3 X=10. X=75. X=7