Answer: x= -2
Step-by-step explanation: use pemdas
10x + 8 = 3(x - 2) distribuite parenthesis
10x + 8 = 3x - 6
10x + 8 = 3x - 6 add like terms
7x +8= -6 add like terms
7x= -14 divide to get x alone
x= -2
How many batteries are in a pack?
You would take that number and divide it by 8.34. That would give you the price per battery. From there you can figure out how many batteries you can buy with only $3 and how much money would be left over.
10 students averaged 80, so the sum of their scores was (10 x 80) = 800
20 students averaged 89, so the sum of their scores was (20 x 89) = 1,780
All together, the sum of all 30 scores was (800 + 1,780) = 2,580
30 students totaled 2,580, so their average was (2,580 / 30) = <em> 86</em> .
