Answer:
B
Step-by-step explanation:
Remark
The easiest way to do this is to Substitute for y in the top equation.
2x + 4y = 18 Divide by 2
2x/2 + 4y/2 = 18/2
x + 2y = 9
Substitute -3x + 2 in for y in the equation above
x + 2(-3x + 2) = 9
x - 6x + 4 = 9
Combine like terms on the left
-5x + 4 = 9
Subtract 4 from both sides.
-5x + 4-4 = 9- 4
-5x = 5
Divide by -5
-5x/-5 = 5/-5
x = - 1
That makes A and C incorrect.
y = -3x + 2
y = -3(-1) + 2
y = 3 + 2
y = 5
The correct answer should be (-1,5) which is B
Answer:
x = 27
Step-by-step explanation:
Given
= 3
Multiply both sides by 9 to clear the fraction
x = 9 × 3 = 27
Answer: m∠ M′N′O′ = 90 degrees
Step-by-step explanation: Hope that helps ! I am not sure if I am right but I think I am !
Answer: B
The series converges because it has a sum of 4.
Step-by-step explanation:
<span>6.5 x 10^6
To answer this question, you need to divide the mass of the sun by the mass of mercury. So
2.13525 x 10^30 / 3.285 x 10^23 = ?
To do the division, divide the mantissas in the normal fashion
2.13525 / 3.285 = 0.65
And subtract the exponents.
30 - 23 = 7
So you get
0.65 x 10^7
Unless the mantissa is zero, the mantissa must be greater than or equal to 0 and less than 10. So multiply the mantissa by 10 and then subtract 1 from the exponent, giving
6.5 x 10^6
So the sun is 6.5 x 10^6 times as massive as mercury.</span>
