Mischa wrote the quadratic equation 0 = –x2 + 4x – 7 in standard form
The standard form of quadratic equation is
When y=0 then the standard equation becomes
Now we compare the given equation with
and find the value of a, b,c
-x^2 can be written as -1x^2
a= -1 , b=4 and c=-7
The value of c is -7
Answer:
The number of red marbles = 152
The number of blue marbles = 228 and
the number of green marbles = 190
Step-by-step explanation:
Let x be the number of red marbles, y be the number of blue marbles and z be the number of green marbles.
It is given that the total marbles = 570.
Therefore, x + y + z = 570 --- (1)
It is also given that the ratio of red to blue marbles is 2 : 3.
Therefore, x : y = 2 : 3
or 3x = 2y --- (2)
It is also given that the ratio of red to green marbles is 4 : 5.
Therefore, x : z = 4 : 5
or 5x = 4z --- (3)
From (2),
From (3),
Substituting the above in (1), we get,
Multiply both sides by 4.
4x + 6x + 5x = 2280
15x = 2280
Divide both sides by 15.
x = 152
Hence,
y =
y = 228
z =
z = 190
Therefore,
The number of red marbles = 152
The number of blue marbles = 228 and
the number of green marbles = 190
<u>Check:</u>
Total number of marbles = 152 + 228 + 190 = 570
Ratio of red to blue marbles = 152 : 228 = 2 : 3
Ratio of red t green marbles = 152 : 190 = 4 : 5