Question

а) 4 – 2(6+6x) – (3 – 9x) + 8x = 9; б) (7x – 28)(7x – 21) = 0 в) 10x + 9 = 22 – 10(3 – (16x – 17) + 13x) – 9x

Answer 1

а) $4-2\left(6+6x\right)-\left(3-9x\right)+8x=9\\4-2\left(6+6x\right)-\left(3-9x\right)+8x-4=9-4\\-2\left(6+6x\right)-\left(3-9x\right)+8x=5\\5x-15=5\\5x-15+15=5+15\\5x=20\\\frac{5x}{5}=\frac{20}{5}\\x=4$

б) $\left(7x-28\right)\left(7x-21\right)=0\\7x-28=0\quad \mathrm{or}\quad \:7x-21=0\\x=4,\:x=3$

в) $10x+9=22-10\left(3-\left(16x-17\right)+13x\right)-9x\\10x+9=21x-178\\10x+9-9=21x-178-9\\10x=21x-187\\10x-21x=21x-187-21x\\-11x=-187\\\frac{-11x}{-11}=\frac{-187}{-11}\\x=17$

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Answer 2

Ответ:

Объяснение:

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Answer 3

a) Let's solve the equation step by step:

4 - 2(6 + 6x) - (3 - 9x) + 8x = 9

First, simplify the expression within parentheses:

4 - 2(12 + 6x) - (3 - 9x) + 8x = 9

4 - 24 - 12x - (3 - 9x) + 8x = 9

Combine like terms:

-20 - 12x - (3 - 9x) + 8x = 9

Next, simplify the expression within parentheses:

-20 - 12x - 3 + 9x + 8x = 9

Combine like terms again:

-23x - 23 = 9

Now, isolate the variable by moving the constant term to the other side:

-23x = 9 + 23

-23x = 32

Finally, solve for x by dividing both sides by -23:

x = 32 / -23

x ≈ -1.3913

b) Let's solve the equation:

(7x - 28)(7x - 21) = 0

To find the solutions, we set each factor equal to zero and solve for x:

7x - 28 = 0 or 7x - 21 = 0

For the first equation, add 28 to both sides:

7x = 28

Divide both sides by 7:

x = 4

For the second equation, add 21 to both sides:

7x = 21

Divide both sides by 7:

x = 3

Therefore, the solutions to the equation are x = 4 and x = 3.

c) Let's solve the equation step by step:

10x + 9 = 22 - 10(3 - (16x - 17) + 13x) - 9x

Start by simplifying the expression within parentheses:

10x + 9 = 22 - 10(3 - 16x + 17 + 13x) - 9x

10x + 9 = 22 - 10(3 + 17 - 16x + 13x) - 9x

10x + 9 = 22 - 10(20 - 3x) - 9x

Next, simplify the expression within the second set of parentheses:

10x + 9 = 22 - 10(20 - 3x) - 9x

10x + 9 = 22 - 200 + 30x - 9x

Combine like terms:

10x + 9 = -178 + 21x

Subtract 21x from both sides:

10x - 21x + 9 = -178

-11x + 9 = -178

Subtract 9 from both sides:

-11x = -187

Finally, solve for x by dividing both sides by -11:

x = -187 / -11

x ≈ 17

Therefore, the solution to the equation is x ≈ 17.