In equation form it would be the following:
2r + 3s = 13.
I believe.
Answer: 40
Step-by-step explanation:
Number of correct questions Sally got = 28 questions
Percentage of correct questions answered= 70% on the exam,
Total number of questions in the exam = Unknown
Let the total questions in the exam be represented as y.
Since Sally got 70% correctly, this will be:
70% of y = 28
70/100 × y = 28
0.7 × y = 28
0.7y = 28
Divide both side by 0.7
0.7y/0.7 = 28/0.7
y = 40
There are 40 questions in the exam.
Answer:
Step-by-step explanation:
a² - b² = (a + b) (a - b)
1)x² - 36 = x² - 6² = (x + 6)(x-6)
2) 4x² - 16 = 4x² - 4*4 = 4(x² - 4)
= 4(x² -2²)
= 4(x + 4)(x-4)
3) 9x² -1 = 3²x² - 1² = (3x)² - 1²
=(3x + 1)(3x - 1)