For this case we must indicate which of the equations shown can be solved using the quadratic formula.
By definition, the quadratic formula is applied to equations of the second degree, of the form:
Option A:
Rewriting we have:
This equation can be solved using the quadratic formula
Option B:
Rewriting we have:
It can not be solved with the quadratic formula.
Option C:
Rewriting we have:
This equation can be solved using the quadratic formula
Option D:
Rewriting we have:
It can not be solved with the quadratic formula.
Answer:
A and C
Question 1:
For this case, the first thing we must do is define variables.
We have then:
x: number of nickels
y: number of dimes
We write the system of equations that adapts to the problem.
We have then:
0.05x + 0.10y = 6.10
x + y = 67
Solving the system we have:
x = 12
y = 55
Answer:
there are 12 nickels
Question 2:
For this case, the first thing we must do is define variables.
We have then:
x: Allan's score
y: Dave's score
We write the system of equations that adapts to the problem.
We have then:
x + y = 375
x = 2y-60
Solving the system we have:
x = 230
y = 145
Answer:
Dave: 145 Allan: 230
A)250 tens
B)1400 hundreds
C)320 tens
D)21000 thousands
