Answer:
I think 15
Step-by-step explanation:
Because there are 3 in every 20 and 20 goes into 100 5 times and 5×3=15
Start by moving all terms to left side of equation 4x^2 - 19x - 30 = 0
Multiply 4 x -30 = -120
Now find two factors of 120 that subtract to give 19... 1 x 120, 2 x 60, 3 x 40, 4 x 30, 5 x 24 ✅
[if it had been +120 we would add the factors looking for 19 which in this case don’t exist]
To get -19 we will need 5 + -24
24 is a multiple of 4 so we can use 4 x -6 and 1 x 5
Giving a factored equation of (4x + 5)(x - 6) = 0 [you should check this by expanding to remove the brackets]
One of the brackets must = zero so the solutions are x = -5/4 or x = 6
Some people look at factors of 4 and -30 and then pair then up to find a sum of -19 but this can take longer to finish.
Answer: An example would be...
Step-by-step explanation:
($5.40+$5)C + ($3.20+$8)xC = Total Amount.
Given
A tea that is 22% jasmine is blended with a tea that is 13% jasmine
Find out the how many pounds of the 22% jasmine tea are used to make 10lb of tea that is 19.3% jasmine.
To proof
Let us assume that the a tea that is 22% jasmine is blended = a
Let us assume that the a tea that is 13% jasmine is blended = b
Total amount of tea made = 10lb
the equation be
a + b = 10
as given
jasmine tea are used to make 10lb of tea that is 19.3% jasmine.
write 22% in the decimal form

= 0.22
write 13% in the decimal form

= 0.13
write 19.3% in the decimal form

= 0.193
than the equation be
0.22a + 0.13b = 0.193 × 10
on simplify
22a + 13b = 193
two equation becomes
22a + 13b = 193 and a + b = 10
multiply a + b = 10 by 13 and subtracted from the 22a + 13b = 193
we get
22a - 13a + 13b -13b = 193 - 130
9a = 63
a = 7lb
put this value in the a + b = 10
we get
7 + b = 10
b = 3lb
Therefore the 22% jasmine tea are used to make 10lb of tea that is 19.3% jasmine is 7 lb .
Hence proved