Answer:
when I worked it out I actually got -1466...
Step-by-step explanation:
Using order of operations you would multiply the 2 by 742, then subtract from left to right. 2 x 742 =1484 and 30 minus that is -1454. Subtracting 12 would give you -1466. I know that's not in the answer choices but that's what I got...
<span><span>13−<span>6x</span></span>=<span><span><span>(<span><span>2x</span>−5</span>)</span>2</span>+3</span></span>Step 1: Simplify both sides of the equation.<span><span><span>−<span>6x</span></span>+13</span>=<span><span><span>4<span>x2</span></span>−<span>20x</span></span>+28</span></span>Step 2: Subtract 4x^2-20x+28 from both sides.<span><span><span><span>−<span>6x</span></span>+13</span>−<span>(<span><span><span>4<span>x2</span></span>−<span>20x</span></span>+28</span>)</span></span>=<span><span><span><span>4<span>x2</span></span>−<span>20x</span></span>+28</span>−<span>(<span><span><span>4<span>x2</span></span>−<span>20x</span></span>+28</span>)</span></span></span><span><span><span><span>−<span>4<span>x2</span></span></span>+<span>14x</span></span>−15</span>=0</span>Step 3: Use quadratic formula with a=-4, b=14, c=-15.<span>x=<span><span><span>−b</span>±<span>√<span><span>b2</span>−<span><span>4a</span>c</span></span></span></span><span>2a</span></span></span><span>x=<span><span><span>−<span>(14)</span></span>±<span>√<span><span><span>(14)</span>2</span>−<span><span>4<span>(<span>−4</span>)</span></span><span>(<span>−15</span>)</span></span></span></span></span><span>2<span>(<span>−4</span>)</span></span></span></span><span>x=<span><span><span>−14</span>±<span>√<span>−44</span></span></span><span>−<span>8</span></span></span></span>
Answer:
Let x be the number of silver medals.
As there were two more gold medals than silver ones, gold medals are x+2
We also know that the number of bronze medals was 4 less than the sum of gold and silver, so if there are x + 2 of gold and x of silver, there are x+x+2-4 of bronze.
Now, we can do an equation, as we know there were a total of 28 medals:
x + x + 2 + x + x + 2 - 4 = 28
And we isolate x:
4x = 28
x = 28/4 = 7
There were 7 silver medals, so there were 9 gold ones (7-2) and 12 of bronze (9+7-4).
Step 1: Trying to factor as a Difference of Squares:
Factoring: x²⁰⁰² - 1
Theory : A difference of two perfect squares, A² - B² can be factored into (A+B) • (A-B)
Proof : (A+B) • (A-B) =
A² - AB + BA - B² =
A² - AB + AB - B²
A² - B²
Note : AB = BA is the commutative property of multiplication.
Note : - AB + AB equals zero and is therefore eliminated from the expression.
Check : 1 is the square of 1
Check: x²⁰⁰² is the square of x¹⁰⁰¹
Factorization is : (x¹⁰⁰¹ + 1) × (x¹⁰⁰¹ - 1)
