Question

1) 11х - 9 = 4х + 19;    2) 7х - 5(2х + 1) = 5х + 15.3)   (14у + 21)(1,8 -0,3у)=0​

Answer 1

Ответ:

вот.

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..... не.

Answer 2

Sure, I'd be happy to help you solve these equations. Let's work through each one step by step.

1. $11x - 9 = 4x + 19$

First, let's isolate the variable $x$ on one side of the equation:

Subtract $4x$ from both sides: $11x - 4x - 9 = 19$

Simplify: $7x - 9 = 19$

Now, add 9 to both sides to isolate $x$: $7x = 28$

Finally, divide both sides by 7 to solve for $x$: $x = \frac{28}{7}$ $x = 4$

So, the solution for the first equation is $x = 4$.

2. $7x - 5(2x + 1) = 5x + 15$

First, distribute the -5 on the left side: $7x - 10x - 5 = 5x + 15$

Simplify: $-3x - 5 = 5x + 15$

Add $3x$ to both sides: $-5 = 8x + 15$

Subtract 15 from both sides: $-20 = 8x$

Divide both sides by 8 to solve for $x$: $x = \frac{-20}{8}$ $x = -\frac{5}{2}$

So, the solution for the second equation is $x = -\frac{5}{2}$.

3. $(14y + 21)(1.8 - 0.3y) = 0$

This equation is a product of two expressions equaling zero. According to the zero-product property, either the first factor $(14y + 21)$ equals zero, or the second factor $(1.8 - 0.3y)$ equals zero.

1st factor: $14y + 21 = 0$ Subtract 21 from both sides: $14y = -21$ Divide both sides by 14: $y = -\frac{21}{14}$ Simplify: $y = -\frac{3}{2}$

2nd factor: $1.8 - 0.3y = 0$ Subtract $1.8$ from both sides: $-0.3y = -1.8$ Divide both sides by $-0.3$ (which is the same as multiplying by $-\frac{1}{0.3}$): $y = \frac{-1.8}{-0.3}$ Simplify: $y = 6$

So, the solutions for the third equation are $y = -\frac{3}{2}$ and $y = 6$.