15 + 2x - 4 = 9x + 11 - 7x
2x + 11 = 2x + 11
always true
2x + 3(4x - 1) = 2(5x + 3) + 4x
2x + 12x - 3 = 10x + 6 + 4x
14x - 3 = 14x + 6
never true
Answer: A
<u>Step-by-step explanation:</u>
f(x) = x³ + 4x² + 7x + 6
possible rational roots are ±{1, 2, 3, 6}
Try x = -2
-2 | 1 4 7 6
<u>| ↓ -2 -4 -6</u>
1 2 3 0 ← remainder is 0 so x = -2 is a root ⇒ (x + 2) = 0
The factored polynomial x² + 2x + 3 = 0 is not factorable so use the quadratic formula to find the roots.
a=1, b=2, c=3
The factors are:
![(x - 2)[x - (-1 + i\sqrt{2})][x - (-1 - i\sqrt{2})]](https://tex.z-dn.net/?f=%28x%20-%202%29%5Bx%20-%20%28-1%20%2B%20i%5Csqrt%7B2%7D%29%5D%5Bx%20-%20%28-1%20-%20i%5Csqrt%7B2%7D%29%5D)
Answer:
2.4 hours
Step-by-step explanation:
Let total work = X
Rate of work done = X ÷ time
Rate of A = X/4
Rate of B = X/6
If they work together, rate is the sum of their individual rates, i.e.
X/4 + X/6
= (3X + 2X)/12 (taking LCM)
=5X/12
Rate = X/time
5X/12 = X/time
time = X÷(5X/12)
time = X × 12/(5X)
time = 2.4 hours
Shortcut:
Product of individual times/sum of individual times
= (4×6)/(4+6)
=24/10
=2.4 hours
<span>Let time taken by Luke to cover the distance = x hours
Speed of Luke = 6 miles per hour
Therefore, Distance covered by Luke = 6x ------(1)
Speed of Micah = 4 miles per hour
Since Micah walked 2 miles before Luke started running, Luke started 1/2 an hour after Micah started.
Therefore time taken by Micah to cover the distance = x+1/2
Distance covered by Micah = 4(x + 1/2) -------(2)
Equating (1) and (2)
6x = 4(x+1/2)
6x = 4x +2
2x = 2
x= 1
Therefore Luke would take 1 hour to cover the distance covered by Micah.</span>
B: 3 & 9
They are the smallest numbers but three still fits into both of them
