Answer:
9 cats
Step-by-step explanation:
x = cat
y = dog
Set up equations.
x + y = 30
4.5x + 8.5y = 219
Multiply first equation by 4.5 and subtract.
4.5x + 4.5y = 135
-(4.5x + 8.5y = 219)
-4y = -84
y = 21
Substitute this y value into the first equation
x + y = 30
x + 21 = 30
x = 9
Answer:
6 and 7
Step-by-step explanation:
6 plus 7 is equivalent to 13 and 6 times 7 is equivalent to 42. 13 plus 29 is equivalent to 42.
Assuming the possible digits are from 0-9, there are 10*9*8 possibilities which come out to 720
Let the number be 'a':
The difference of the square of a number and 4
a^2 -4
is equal to 3 times that number.
= 3*a
a^2 -4 =3a
a^2 -3a -4=0
(a-4) (a+1)=0
solutions are: 4 and -1
