Question

(67-y)•7+20=90; (308-(25+x) •7) ÷5=7

Answer 1

Вот первое уравнение, со вторым не понятно как-то

Answer 2

это 2 пример.

(308-(25+х)×7)÷5=7

(308-(175+7х))÷5=7

(308-175-7х)÷5=7

(133-7х)÷5=7

$\frac{133 - 7x}{5} = 7$

133-7х=35

-7х=35-133

-7х=-98

х=14

Answer 3

To solve the equations:

1. (67-y)•7+20=90

Start by simplifying the left side of the equation:

(67-y)•7+20 = 469 - 7y + 20 = 489 - 7y

Now the equation becomes:

489 - 7y = 90

Subtracting 489 from both sides, we get:

-7y = -399

Dividing both sides by -7, we get:

y = 57

Therefore, the solution to the first equation is y = 57.

2. (308-(25+x) •7) ÷5=7

First, simplify the left side of the equation:

(308-(25+x) •7) ÷5 = (308-175-7x) ÷5 = (133-7x) ÷5

Now the equation becomes:

(133-7x) ÷5 = 7

Multiplying both sides by 5, we get:

133 - 7x = 35

Subtracting 133 from both sides, we get:

-7x = -98

Dividing both sides by -7, we get:

x = 14

Therefore, the solution to the second equation is x = 14.