The quadratic equations and their solutions are;
9 ± √33 /4 = 2x² - 9x + 6.
4 ± √6 /2 = 2x² - 8x + 5.
9 ± √89 /4 = 2x² - 9x - 1.
4 ± √22 /2 = 2x² - 8x - 3.
Explanation:
- Any quadratic equation of the form, ax² + bx + c = 0 can be solved using the formula x = -b ± √b² - 4ac / 2a. Here a, b, and c are the coefficients of the x², x, and the numeric term respectively.
- We have to solve all of the five equations to be able to match the equations with their solutions.
- 2x² - 8x + 5, here a = 2, b = -8, c = 5. x = -b ± √b² - 4ac / 2a = -(-8) ± √(-8)² - 4(2)(5) / 2(2) = 8 ± √64 - 40/4. 24 can also be written as 4 × 6 and √4 = 2. So x = 8 ± 2√6 / 2×2= 4±√6/2.
- 2x² - 10x + 3, here a = 2, b = -10, c = 3. x =-b ± √b² - 4ac / 2a =-(-10) ± √(-10)² - 4(2)(3) / 2(4) = 10 ± √100 + 24/4. 124 can also be written as 4 × 31 and √4 = 2. So x = 10 ± 2√31 / 2×2 = 5 ± √31 /2.
- 2x² - 8x - 3, here a = 2, b = -8, c = -3. x = -b ± √b² - 4ac / 2a = -(-8) ± √(-8)² - 4(2)(-3) / 2(2) = 8 ± √64 + 24/4. 88 can also be written as 4 × 22 and √4 = 2. So x = 8 ± 2√22 / 2×2 = 4± √22/2.
- 2x² - 9x - 1, here a = 2, b = -9, c = -1. x = -b ± √b² - 4ac / 2a = -(-9) ± √(-9)² - 4(2)(-1) / 2(2) = 9 ± √81 + 8/4. x = 9 ± √89 / 4.
- 2x² - 9x + 6, here a = 2, b = -9, c = 6. x = -b ± √b² - 4ac / 2a = -(-9) ± √(-9)² - 4(2)(6) / 2(2) = 9 ± √81 - 48/4. x = 9 ± √33 / 4 .
Because 1/2 of 6 =1/3 and 1/2×1/3=1/6
Answer:
, D
Step-by-step explanation:
3 if x is greater than or equal to 1 is nothing. That leaves us with 
if x<1. If you substitute in 1 for x, you get 3, but of course that isn't possible, so the range is , which is D.
Answer:
It took 1.2 hours to get to the store
Step-by-step explanation:
Let the time taken to reach the store be t₁
Let the time taken to come back be t₂
Let the speed to and from store = s₁ and s₂ respectively
let the distance to the store = d
To the store:
Back from the store:
We are told that total time (t₁ + t₂) = 2 hours
t₁ + t₂ = eqn (1) + eqn (2)
∴ length of trip to the store = t₁
from eqn (1)
So first, you want to open the parenthesis here.
So, to do that, first look at the symbol before the parenthesis.
In this case it's a -.
So when it's a -, reverse the symbol inside the parenthesis. (This is because if you don't you're subtracting 2x and then adding 8, when really you're subtracting both 2x and 8.)
So,
9x - 2x - 8
Or simplified,
7x - 8
