She got 54 questions rights.
Explanation: Multiply 60 by .9. The decimal is the percentage you need to find, example (30*.3) .3 is thirty percent.
Answer
8p∠-8
Step-by-step explanation:
Answer:
x = - 3
y = 4
Step-by-step explanation:
x + y = 1 | (-3)
x + 3y = 9
- 3x - 3y = - 3
x + 3y = 9
_____________
- 3x + x = 9 - 3
- 2x = 6
2x = - 6
x = - 3
- 3 + y = 1
y = 1 + 3
y = 4
Answer:
Original number 26.
Step-by-step explanation:
xy - two-digit number
1) x + y = 8
2) Original two-digit number can be written as
10*x + y
3) If the digits interchanged yx,
then the new number can be written as
10*y + x
4) Double the original number is
2*(10*x + y)
5) New number is 10 more than double the original number
(10*y + x) - (2*(10*x + y)) = 10
6) Now we have the system of 2 equations:
x + y = 8
(10*y + x) - (2*(10*x + y)) = 10 -----> 10y + x - (20x + 2y) = 10 ---> 8y - 19x = 10
x = 8 - y
8y - 19(8 - y) = 10
8y - 152 +19y = 10
27y = 162
y = 6
x = 8 - y = 8 - 6 = 2
x = 2
So, x =2, y = 6.
Original number 26.
Check:
Original number 26.
New number 62.
Double of the original number = 2*26= 52.
New number is 10 more than double the original number :
62 - 52 = 10 True
