For each question, find y when x=-3Then find x when y=21. For y=6x+8; y=___ and x=____ 2. For y=2/3x; y=____ and x=____3. For y= -x+5; y=____ and x=____4. For y=3/4x-2 1/2; y=_____ and x=____5. For y= 1.5x+11; y=____ and x=____

Respuesta :

We have the expression

[tex]y=\frac{3}{4}x-2\frac{1}{2}[/tex]

If x=3, then the expression takes the value:

[tex]\begin{gathered} y=\frac{3}{4}(3)-2\frac{1}{2} \\ =\frac{9}{4}-\frac{5}{2} \\ =\frac{18-20}{8} \\ =\frac{-2}{8} \\ =-\frac{1}{4} \end{gathered}[/tex]

Now, if y=2 then:

[tex]\begin{gathered} 2=\frac{3}{4}x-2\frac{1}{2} \\ 2+2\frac{1}{2}=\frac{3}{4}x \\ 2+\frac{5}{2}=\frac{3}{4}x \\ \frac{4+5}{2}=\frac{3}{4}x \\ \frac{9}{2}=\frac{3}{4}x \\ x=(\frac{4}{3})(\frac{9}{2}) \\ x=\frac{36}{6} \\ x=6 \end{gathered}[/tex]