A+3b = 7, c= 3 , then the value of a+3 (b+c ) = a) 10
b) 16
c) 21
d) 30
step by step pls

Compare these two waves: the blue and orange waves have the same pitch, but the blue wave is louder. the blue and orange waves have the same volume, but the blue wave has a higher pitch. the orange wave has a higher pitch, but the blue wave is louder. the blue wave has a higher pitch, but the orange wave is louder.

During a bike challenge riders have to collect various colored ribbons each 1/2 mile they collect a red ribbon each eighth mile they collect a green ribbon and each quarter mile they collect a blue ribbion wich colors of ribion will be collected at the 3/4 markrer

Pranza plotted point a in the coordinate plane below.