2x^2-7=4
subtract 4 from both sdies
2x^2-11=0
therefor
2x^2=11
divide by 2
x^2=5.5
square root both sdies
x=-2.345 or 2.345
Answer:
25+24= 49coins 49÷2.5 is 19.5 so there are 19.5 dimes in the bag I believe
x + 4 = 15
- 4 -4
x = 11
You would subtract 4 because you need to isolate the x to get the value of x. You would subtract it to both sides because whatever you do on one side, you have to do it to the other side.
3 (x+7)
multiply 3 to both x and 7
3x+21