Answer: 7 years
Step-by-step explanation:
let x be the age of Mary
so John's age will be 2x
the equation becomes
2x+x=21
3x=21
x=21/3
x=7
Answer:
5 lb 11⅓ oz
Step-by-step explanation:
First, convert the weight at birth from pound and ounces to just ounces.
8 lb × 16 oz/lb + 9 oz = 137 oz
The baby doubles its weight in the first six months. That means its weight increases by 137 oz over 6 months. To find how much weight was gained in 4 months, write a proportion.
137 / 6 = x / 4
6x = 548
x = 91 ⅓
The baby gained 91 ⅓ oz in 4 months, or 5 lb 11⅓ oz.
Answer:
x = 
Step-by-step explanation:
Given
19 -
= 7 ( subtract 19 from both sides )
-
= - 12
Multiply both sides by - 4 to clear the fraction and the negative signs
5x + 6 = 48 ( subtract 6 from both sides )
5x = 42 ( divide both sides by 5 )
x = 
The probability of the black puppy chosen would be 1 in 4.