Sign In
Ask Question
Mathematics
Brenna Gardner
18 November, 13:58
What times what equals 30 but add to get 40?
+3
Answers (
2
)
Andres Marshall
18 November, 15:10
0
Lets call those two unknown numbers a, b and write the info in the problem as equations:
a*b = 30
a + b = 40
lets solve for a in the second equation and substitute in the first:
a + b = 40
a = 40 - b
therefore:
a*b = 30
(40 - b) b = 30
40b - b^2 = 30
b^2 - 40b + 30 = 0
if we apply the general quadratic equation to solve we have:
b = (40 + - √ (1600 - 120)) / 2
b = (40 + - √ (1480)) / 2
b = (40 + - 38.47) / 2
There are two solutions:
b1 = (40 + 38.47) / 2
b1 = 39.24
b2 = (40 - 38.47) / 2
b2 = 0.765
lets use the second solution b2 = 0.765, and substitute in the first equation to find a:
a*b = 30
a*0.765 = 30
a = 30/0.765
a = 39.216
so the numbers are 39.216 and 0.765
Comment
Complaint
Link
Sunday
18 November, 16:22
0
(15x2) = 30, (30 + 10) = 40 ... (P. E. M. D. A. S)
Comment
Complaint
Link
Know the Answer?
Answer
Not Sure About the Answer?
Get an answer to your question ✅
“What times what equals 30 but add to get 40? ...”
in 📙 Mathematics if there is no answer or all answers are wrong, use a search bar and try to find the answer among similar questions.
Search for Other Answers
You Might be Interested in
A car can travel 32 miles and he's going to gas the function D of X equals 32X represents a distance do you have extra miles that the car can travel with ex-con to gas the car
Answers (1)
What is the balance as result of having a credit of $84 and a debit of $29
Answers (1)
75% of 72 hours find the quantity represented by each percent
Answers (2)
What is the value 1/2 * 3+5.2y when x=2 and y=3
Answers (2)
Jason drives 400 miles in 10 hours. Which unit of measure is most appropriate for speed?
Answers (2)
New Questions in Mathematics
In the following expression which terms can be combined? -30p + 28w - 56 1) - 30p - 56 2) - 30p + 28w 3) 28w - 56 4) None of the above
Answers (1)
A number is equal to the product of - 2 and the difference in another number (n) and 5. The sum of the number is 16. What is the second number?
Answers (1)
Factors of 72 that add up to 18
Answers (1)
Which line below has a lower y-intercept than the line y = 2x - 1? y + 3 = 3 (x - 4) y + 3 = 1 (x + 4) y - 3 = negative - (x - 4) y - 3 = (x - 4)
Answers (1)
Mr. Gutierrez usually takes 3/4 hour to drive home from work. Because of a traffic jam, he took an extra 1 2/3 hours to get home one night. How long did that ride take him
Answers (1)
Home
»
Mathematics
» What times what equals 30 but add to get 40?
Sign In
Sign Up
Forgot Password?