Answer:
-9.2
Step-by-step explanation:
3x+4x+5x=90
combine like terms
12x = 90
divide by 12
x = 7.5
sides: 3(7.5) ,4(7.5) ,5(7.5)
22.5, 30, 37.5
Answer: the second one
Step-by-step explanation:
cuz i say so
Number of +ve integers divisible by 2 less than or equal to 210=a=210/2=105
number of +ve integers divisible by 3 less than or equal to 210=b=210/3=70
number of +ve integers divisible by 7 less than or equal to 210=c=210/7=30
number of +ve integers divisible by 2&3 less than or equal to 210=d=210/6=35
number of +ve integer divisible by 2&7 less than or equal to 210=e=210/14=15
number of +ve integer divisible by 3&7 less than or equal to 210=e=210/21=10
number of +ve integer divisible by 2&7&3 less than or equal to 210=e=210/42=5
<span>number of positive integers not larger than 210 and divisible by 2, 3 or 7=105+70+30-(35+15+10)+5
=150
so numbers not divisible=total-150
=210-150
=</span>60
200 can be rounded down to 200, which is easy to add with. Thus, an estimate is 222+200=422.
Alternatively, you could round 222 up a bit, to get 225+200=425. This is actually the correct answer, but this rounding doesn't make the calculation easier, so if you needed a quick estimate I'd go with the first option.
