Solve {l}{3x+7*4x-3.6x-1*5x=90}{y=74}{text{Solvefor}ztext{where}}{z=y}

$$\left. \begin{array} { l } { 3 x + 7 \cdot 4 x - 3.6 x - 1 \cdot 5 x = 90 }\\ { y = 74 }\\ { \text{Solve for } z \text{ where} } \\ { z = y } \end{array} \right.$$

Solve for x, y, z

$$z=74$$

Solution Steps

Consider the first equation. Multiply 7 and 4 to get 28.

$$3x+28x-3.6x-1\times 5x=90$$

Combine 3x and 28x to get 31x.

$$31x-3.6x-1\times 5x=90$$

Combine 31x and -3.6x to get 27.4x.

$$27.4x-1\times 5x=90$$

Multiply 1 and 5 to get 5.

$$27.4x-5x=90$$

Combine 27.4x and -5x to get 22.4x.

$$22.4x=90$$

Divide both sides by 22.4.

$$x=\frac{90}{22.4}$$

Expand \frac{90}{22.4} by multiplying both numerator and the denominator by 10.

$$x=\frac{900}{224}$$

Reduce the fraction \frac{900}{224} to lowest terms by extracting and canceling out 4.

$$x=\frac{225}{56}$$

The system is now solved.

$$x=\frac{225}{56} y=74 z=74$$