Answer:
-13
Step-by-step explanation:
Opposite of 9t = -9t
Taking the sum of 9t - 13 and -9t
Sum = 9t - 13 + (-9t)
Sum = 9t - 13 - 9t
Sum = 9t-9t - 13
Sum = -13
Hence the expression in standard form is -13
Answer:
Step-by-step explanation:
x² + 6x + 1 = 0
a = 1 , b = 6 , c = 1
Answer:
7 = 49 ÷ r
Step-by-step explanation:
To find the equation that is true when r = 7, we need to find a number after the equals sign that is a multiple of 7.
Multiples of 7:
7, 14, 21, 28, 35, 42, 49, 56, 63, 70, 77...
Therefore, the only answer option in which the number after the equals sign is a multiple of 7 is:
7 = 49 ÷ r
To prove this, input r = 7 into each of the equations:
6 = 30 ÷ r
⇒ 6 = 30 ÷ 7
⇒ 6 ≠ 4.285... ← incorrect!
7 = 54 ÷ r
⇒ 7 = 54 ÷ 7
⇒ 7 ≠ 7.714... ← incorrect!
7 = 49 ÷ r
⇒ 7 = 49 ÷ 7
⇒ 7 = 7 ← correct!
9 = 72 ÷ r
⇒ 9 = 72 ÷ 7
⇒ 9 ≠ 10.285... ← incorrect!
