Answer:
Step-by-step explanation:
15 x 7 = 105
The gap is either 9 x 7 =63 or 12 x 7 = 84
105 - 84 = 21
105 - 63 = 42
So the shaded area is either is 21 or 42
Answer:
A1) 125
A2) 47.5%
B) 30
Step-by-step explanation:
Remember 'of' in this sentence means times(*). % shows a certain number/100.
a1) 48% 'of' what number is 60?
(let unknown number be x)
48/100 *x=60
Solve the equation, and the answer is x=125
a2) what percentage 'of' 120 is 57?
(let the unknown percentage be x)
(x/100)*120=57
x=47.5%
b) 24 students= 80% of the total number of students
1%=24/80
100% of the total number of students=30
So, there are total of 30 students
<h3>Answer:</h3>
±12 (two answers)
<h3>Explanation:</h3>
Suppose one root is <em>a</em>. Then the other root will be -3<em>a</em>. The product of the two roots is the ratio of the constant coefficient to the leading coefficient:
(<em>a</em>)(-3<em>a</em>) = -27/4
<em>a</em>² = -27/(4·(-3)) = 9/4
<em>a</em> = ±√(9/4) = ±3/2
Then the other root is
-3<em>a</em> = -3(±3/2) = ±9/2 . . . . . . the roots will have opposite signs
We know the opposite of the sum of these roots will be the ratio of the linear term coefficient to the leading coefficient: b/4, so ...
-(a + (-3a)) = b/4
2a = b/4
b = 8a = 8·(±3/2)
b = ±12
_____
<em>Check</em>
For b = 12, the equation factors as ...
4x² +12x -27 = (2x -3)(2x +9) = 0
It has roots -9/2 and +3/2, the ratio of which is -3.
For b = -12, the equation factors as ...
4x² -12x -27 = (2x +3)(2x -9) = 0
It has roots 9/2 and -3/2, the ratio of which is -3.
