Answer:
33+12t−21t^2
Step-by-step explanation:
(2t-7)²-(5t-4)²
Use binomial theorem (a−b)^2 = a^2−2ab+b^2 to expand (2t-7)².
4t^2−28t+49−(5t-4)²
Use binomial theorem (a−b)^2 = a^2−2ab+b^2 to expand (5t-4)².
4t^2−28t+49−(25t^2−40t+16)
To find the opposite of 25t^2
−40t+16, find the opposite of each term.
4t^2−28t+49−25t^2−40t+16
Combine 4t^2 and −25t^2 to get −21t^2.
−21t^2−28t+49+40t−16
Combine −28t and 40t to get 12t.
−21t^2+12t+49−16
Subtract 16 from 49 to get 33.
−21t^2+12t+33
Swap terms to the left side.
33+12t−21t^2
I hope this helped!
Let's solve your equation step-by-step.<span><span><span><span>2<span>x2</span></span>−<span>3x</span></span>−4</span>=0</span>Step 1: Use quadratic formula with a=2, b=-3, c=-4.<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>(<span>−3</span>)</span></span>±<span>√<span><span><span>(<span>−3</span>)</span>2</span>−<span><span>4<span>(2)</span></span><span>(<span>−4</span>)</span></span></span></span></span><span>2<span>(2)</span></span></span></span><span>x=<span><span>3±<span>√41</span></span>4</span></span><span><span>x=<span><span>34</span>+<span><span><span><span>14</span><span>√41</span></span><span> or </span></span>x</span></span></span>=<span><span>34</span>+<span><span><span>−1</span>4</span><span>√<span>41</span></span></span></span></span>
Answer:
53.57%
Step-by-step explanation:
We have to calculate first the specific number of events that interest us, if at least 3 are girls, they mean that 2 are boys, therefore we must find the combinations of 3 girls of 5 and 2 boys of 3, and multiply that, so :
# of ways to succeed = 5C3 * 3C2 = 5! / (3! * (5-3)!) * 3! / (2! * (3-2)!)
= 10 * 3 = 30
That is, there are 30 favorable cases, now we must calculate the total number of options, which would be the combination of 5 people from the group of 8.
# of random groups of 5 = 8C5 = 8! / (5! * (8-5)!) = 56
That is to say, in total there are 56 ways, the probability would be the quotient of these two numbers like this:
P (3 girls and 2 boys) = 30/56 = 0.5357
Which means that the probability is 53.57%
The answer is 91 toys sold, make
the number ab where a is the 10th digit and b is the first digit. The
value is 10a + b that can expressed as 10 (3) + 4 = 34
Let the price of each item: xy
10x + y
He accidentally reversed the
digits to: 10b + a toys sold at 10y + x rupees per toy. To get use the formula,
he sold 10a + b toys but thought he sold 10b + a toys. The number of toys that
he thought he left over was 72 items more than the actual amount of toys left
over. So he sold 72 more toys than he thought:
10a + b =10b + a +72
9a = 9b + 72
a = b + 8
The only numbers that could work
are a = 9 and b = 1 since a and b each have to be 1 digit numbers. He reversed
the digits and thought he sold 19 toys. So the actual number of toys sold was
10a + b = 10 (9) + 1 = 91 toys sold. By checking, he sold 91 – 19 = 72 toys
more than the amount that he though the sold. As a result, the number of toys
he thought he left over was 72 more than the actual amount left over as was
stated in the question.
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2x + 3y = 1470
3y = -2x + 1470
y = -2/3x + 490 is the equation in slope intercept form.
slope = -2/3
y intercept = 490
