Answer:
49
Step-by-step explanation:
substitute b = - 6 and c = 7 into the expression and evaluate
c - 7b = 7 - (7 × - 6) = 7 - (- 42) = 7 + 42 = 49
ANSWER
A) 9.4 * 10^-8, 9.25 * 10^-6, 2.5 * 10^3, 7* 10^3
EXPLANATION
The numbers are given in standard form.
The first criteria we will use to order them is the exponents.
The bigger the exponents the bigger the number.
The second criteria is that, if the exponents of any two numbers are the same, then we use the numbers multiplying the powers of 10 to order.

The correct choice is A.
Answer:
(-1,8)
(4,-27)
Step-by-step explanation:
y+7x=1
Let x = -1 and find y
y+7(-1)=1
y -7 =1
Add 7 to each side
y-7+7 = 1+7
y = 8
(-1,8)
Let x = 4 and find y
y+7(4)=1
y +28 =1
Subtract 28 from each side
y+28-28 = 1-28
y = -27
(4,-27)
Answer: 231
<u>Explanation:</u>
Liwen Celina
5x 6x
5x - 21 =
6x
5x - 21 = 4x
<u>-4x +21</u> <u>-4x +21 </u>
x = 21
Liwen: 5x = 5(21) = 105
Celina: 6x = 6(21) =<u> 126</u>
Total: 231