Part A = She incorrectly add 1 (4/4) with 3/4, so instead of getting 7/4 she got 8/4.
Part B=She needs 28/4 (7) cups for 4 batches because 4/1x7/4=28/4.
3x²+x-5=0
a = 3, b = 1, c= -5
-> ∆ ( delta ) = b²-4ac = 61 > 0
-> x1 =( -b+√∆ )÷ 2a =...
x2 = (-b-√∆)÷2a =...
p/s: do your teachers teach you how to use ∆ ( delta ) in maths calculation ? i live in europe and our teachers teach us that way. however, it is a rịght and fast way. you should learn it.
<span>204
First, lookup a standard normal table and see what the z-score is for 0.025 (one half of 100% - 95%) to allow for equal sized tails. You should find that the z-score is 1.96. That means that 95% of the time, the value should be within 1.96 standard deviations of the mean. Now let's calculate the standard deviation.
800 is 800 - 1200 = -400 to the left of the mean of 1200.
1600 is 1600 - 1200 = 400 to the right of the mean of 1200.
So we are an equal distance of 400 on both sides of the mean. And we know from the z-score of 1.96, that we're 1.96 standard deviations from the mean. So a little division will give us the standard deviation. Which is:
400 / 1.96 = 204.0816327
So the standard deviation of the light bulbs is 204</span>
Answer: a=36; b=18
Step-by-step explanation:
1. You know that the sum of two numbers is 54, then, you have:
a+b=54
2. According to the problem, the larger number is 18 more than the sampler number, this can be expressed as following:
a=b+18
3. Then, you must substitute the second equation into the first equation and solve for b:
b+18+b=54
b=18
4. Then the value of a is:
a+18=55
a=36