Step-by-step explanation:
4x2=−9x−4
Step 1: Subtract -9x-4 from both sides.
4x2−(−9x−4)=−9x−4−(−9x−4)
4x2+9x+4=0
For this equation: a=4, b=9, c=4
4x2+9x+4=0
Step 2: Use quadratic formula with a=4, b=9, c=4.
x=
−b±√b2−4ac
2a
x=
−(9)±√(9)2−4(4)(4)
2(4)
x=
−9±√17
8
x=
−9
8
+
1
8
√17 or x=
−9
8
+
−1
8
√17
Answer:
18 L
Step-by-step explanation:
Given : she must mix a solution of 67% herbicide with a solution of 46% herbicide to form 42 liters of a 55% solution.
To Find: How much of the 67% solution must she use?
Let x = amount of 67% solution needed
Then 42-x=amount of 46% solution needed
Now we know that the pure herbicide in the 67% solution
So, pure herbicide = (0.67x)
The amount of pure herbicide in the 46% solution (0.46(42-x))
Now 42 liters of a 55% solution = (0.46(42-x))
So,
Amount of 67% solution + Amount of 46% solution = 42 liters of a 55% solution
⇒0.67x+0.46(42-x)=0.55*42
⇒0.67x+19.32-0.46x=23.1
⇒0.21x=3.78
⇒
⇒x = 18 liters
Hence she use 18 liters of the 67% solution
Option B:
Both n and m must be rational.
Solution:
Given information:
Sum of two numbers, n and m are rational.
<u>To find which statements are true:</u>
Option A: Both n and m may be rational but do not have to be.
It is not true because n and m given is rational.
It have to be rational.
Option B: Both n and m must be rational.
Yes, n and m must be rational then only the sum of numbers are rational.
It is true.
Option C: Both n and m must be irrational.
Sum of irrationals will be sometimes irrational and sometimes can't add.
So it is not true.
Option D: One number is rational and the other is irrational.
Rational and irrational cannot be add.
So it is not true.
Option B is true.
Both n and m must be rational.
Answer:
It's all about the brackets.
Step-by-step explanation:
If we do (-4)^2, the brackets make it -4 x -4 and the two negatives make a positive of 16.
If we do -4^2, that means that the 4 is squared before putting the minus sign there so you have 4x4 = 16 then put the minus to get -16.
Hope this helps!
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