Answer:
[tex]x = 13[/tex]
[tex](4x - 1) = 51[/tex]
[tex](3x) = 39[/tex]
Step-by-step explanation:
[tex](4x - 1) + (3x) + 90 = 180[/tex]
[tex](4x - 1) + (3x) = 180 - 90[/tex]
[tex](4x - 1) + (3x) = 90[/tex]
[tex]4x - 1 + 3x = 90[/tex]
[tex]7x - 1 = 90[/tex]
[tex]7x = 90 + 1[/tex]
[tex]7x = 91[/tex]
[tex] \frac{7x}{7} = \frac{91}{7} [/tex]
[tex]x = \frac{91}{7} [/tex]
[tex]x = 13[/tex]
[tex][/tex]
[tex](4x-1)=4(13) - 1[/tex]
[tex](4x-1)=52 - 1[/tex]
[tex](4x-1)=51[/tex]
[tex](3x)=3(13)[/tex]
[tex](3x)=39[/tex]