Question

solve for the unknown:
a*9=45
question 8 (1 point)
solve for the unknown:
x/4=5
question 9 (1 point)
solve for the unknown:
3*x+4=19

Explanation:

First Equation ($a \times 9 = 45$)

Step1: Isolate the variable \(a\)

To solve for \(a\) in the equation \(a \times 9 = 45\), we divide both sides of the equation by 9. This is based on the inverse operation of multiplication, which is division. So we have:

$$ \frac{a \times 9}{9}=\frac{45}{9} $$

Step2: Simplify both sides

Simplifying the left - hand side, the 9 in the numerator and denominator cancels out, leaving \(a\). For the right - hand side, \(\frac{45}{9} = 5\).

Step1: Isolate the variable \(x\)

To solve for \(x\) in the equation \(\frac{x}{4}=5\), we multiply both sides of the equation by 4. This is based on the inverse operation of division, which is multiplication. So we get:

$$ x=\ 5\times4 $$

Step2: Calculate the result

Calculating the right - hand side, \(5\times4=20\).

Step1: Subtract 4 from both sides

First, we want to isolate the term with \(x\). So we subtract 4 from both sides of the equation \(3x + 4=19\). This gives us:

$$ 3x+4 - 4=19 - 4 $$

Simplifying both sides, we have \(3x=15\).

Step2: Divide both sides by 3

Next, we divide both sides of the equation \(3x = 15\) by 3 to solve for \(x\).

$$ \frac{3x}{3}=\frac{15}{3} $$

Simplifying, we get \(x = 5\).

Answer:

\(a = 5\)

Second Equation ($\frac{x}{4}=5$)