The general equation with quadratic equation is “ax^2 + bx + c = 0”. Therefore, this equation can be standardized to “x^2 - 7x - 8 = 0”
10,11,15 is not right triangle
30,40,50 is right triangle
9,13,16 is not right angel
16,30,34 is right triangle
Answer:
about 29.7 minutes
Step-by-step explanation:
If it take c minutes for Charles to mow the lawn by himself, it takes c+16 minutes for Peter. The two of them working together can mow in one minute this fraction of the entire lawn:
1/c + 1/(c+16) = 1/18
Multiplying by 18c(c+16), we get ...
18(c +16) + 18(c) = c(c+16)/18
36c +288 = c^2 +16c
c^2 -20c = 288 . . . . . subtract 36c
c^2 -20c +100 = 388 . . . . . add (20/2)^2 = 100 to complete the square
(c -10)^2 = 388
c = 10 +√388 ≈ 29.6977 . . . . . take the positive square root
It takes Charles about 29.7 minutes to mow the lawn by himself.
The property used is: Multiplicative identity
Step-by-step explanation:
We need to identify the property in the equation : 
The property used is: Multiplicative identity
Multiplicative identity
The multiplicative identity property is defined as if you multiply a number by 1, the result of multiplication is that original number.
In the given expression -3 is multiplied by 1 to get -3 so, multiplicative identity.
Keywords: Properties of Multiplication
Learn more about Properties of Multiplication at:
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