Question

23(15-y)=12. (a+45):11=12. 144:(71-b)=9​

Answer 1

23(15-у)=12

15-у=4

-у=4-15

-у=-11

у=1

с)

(а+45):11=12

а+45=132

а=132-45

а=87

д)

144:(71-b)=9

144:(71-b)=9 b≠71

144=9(71-b)

16=71-b

b=71-16

b=55, b≠71

b=55

Answer 2

Let's solve each equation step by step:

1. 23(15-y) = 12:

Start by distributing the 23 on the left side of the equation:

345 - 23y = 12

Next, isolate the variable by subtracting 345 from both sides:

-23y = 12 - 345

Simplify the right side:

-23y = -333

To solve for y, divide both sides by -23:

y = -333 / -23

Simplifying the division gives:

y ≈ 14.478

So the solution for the first equation is y ≈ 14.478.

2. (a + 45) / 11 = 12:

Multiply both sides of the equation by 11 to eliminate the division:

a + 45 = 12 * 11

Simplify the right side:

a + 45 = 132

Now, isolate the variable a by subtracting 45 from both sides:

a = 132 - 45

Simplifying the right side gives:

a = 87

Therefore, the solution for the second equation is a = 87.

3. 144 / (71 - b) = 9:

Multiply both sides of the equation by (71 - b) to eliminate the division:

144 = 9 * (71 - b)

Distribute the 9 on the right side:

144 = 639 - 9b

Move the variable term to one side by subtracting 639 from both sides:

-495 = -9b

To solve for b, divide both sides by -9:

b = -495 / -9

Simplifying the division gives:

b = 55

Thus, the solution for the third equation is b = 55.

To summarize the solutions:

• The first equation: y ≈ 14.478
• The second equation: a = 87
• The third equation: b = 55