Answer:
1.a=5,b=-2
Step-by-step explanation:
2x+a=5-bx
divide by 2
[tex]x+\frac{a}{2}=\frac{5}{2}+\frac{-b}{2}x\\for~ to~ have ~infinite ~solutions\\\frac{a}{2}=\frac{5}{2}\\a=5\\1=\frac{-b}{2}\\b=-2[/tex]
or
equate the coefficients of like terms
-b=2
b=-2 (coefficient of x)
a=5 (constant terms)
2.
72°
external angle= sum of two opposite internal angles.
∠2=42+30=72°
