Answer:
6+6=12 and x= -1
Step-by-step explanation:
8-7+x=0
1+x=0
x= -1
Answer:
22%
Step-by-step explanation:
1000-780=220
220/1000=0.22, or 22%
Answer:
7
Step-by-step explanation:
x-3=4
x=4+3
x=7
The ratio is 4:3:1
let the ratio be 4x:3x:x
according to the question,4x+3x+x=40
8x=40
x=5
therefore amount of gravel=x*4=5*4=20

amount of sand=5*3=15

amount of cement=5*1=5