Answer:
John answered 50 questions.
Step-by-step explanation:
Although five of John's answers were incorrect, 90% of his answers were correct.
This means that 5 is 100 - 90% = 10% of the total number of questions, n. So



John answered 50 questions.
Number 1 is Rio Grande and number 2 is St. Lawrence River
Step-by-step explanation:
Answer:
A = 360
B= 180
C=270
Step-by-step explanation:
X+x²=30
x²+x-30=0
(x+6)(x-5)=0
x=-6 or x=5