It can help because 9×4 =36, and 9×8=72. if you divide 72 by 2 you get 36 which is the answer to 9 ×4. basically because nine is the same in both problems you are multiplying by 4 (and you know 4 is half of 8) you can assume that multiplying the sum of 4 and 9 that you will get the sum of 8 and 9.
This situation can be represented by
y = 33x + 223
y = 32x + 239
I still like substitution, so let’s plug in 33x + 223 into the second equation
33x + 223 = 32x + 239
Move the terms into appropriate sides
33x - 32x = 239 - 223
Combine like terms
x = 16
Then plug in x for any equation
y = 32(16) + 239
y = 751
Erin will have to swim 16 laps for a total of 751 meters
Answer:
1st= 47/7 or 6.71
2nd= 48/7 or 6.857
Step-by-step explanation:
1st number =X and 2nd number = Y
According to question, X+7=2Y
20+Y=4X
X=2Y-7 (from 1st condition)
putting in it second
20+Y=4(2Y-7)
20+Y=8Y-28
20+28=8Y-Y
48=7Y
Y=48/7
so X=2(48/7)-7
=96-49/7
47/7
Answer:
3/8
Step-by-step explanation:
3 1/3 = 10/3
1 1/4 = 5/4
Remember when dividing by a fraction you can also multiply by its reciprocal meaning flip the numerator and denominator.
so
(3 1/3) / (1 1/4) = (10/3) / (5/4) = (10/3) x (4/5) which is the same as (3/10) x (5/4)
= (3 x 5) / (10 x 4) = 15 / 40
the numerator and denominator have a common factor of 5 so divide the numerator and denominator by 5
15 / 40 = 3/8
