Answer:
Number of dogs = 6
Number of burgers = 11
Step-by-step explanation:
Number of dogs = x
Number of burgers = 2x - 1
Cost of a dog = $ 1.50
Cost of 'x' dogs = 1.5x
Cost of a burger = $ 2
Cost of (2x - 1) burger = (2x -1) * 2 = 2x *2 - 1*2
= 4x - 2
Total amount collected = $ 31
1.5x + 4x - 2 = 31 {add 2 to both sides}
1.5x + 4x = 31 + 2
1.5x+ 4x = 33
5.5x = 33
x = 33/5.5
x = 6
Number of dogs = 6
Number of burgers = 2*6 - 1 = 12 - 1 = 11
I know of two ways to solve quadratic equations. The first is through factoring. Let us take the example (x^2)+2x+1=0. We can factor this equation out and the factors would be (x+1)(x+1)=0. To solve for the roots, we equate each factor to 0, that is
x+1=0; x+1=0
In this case, the factors are the same so the root of the equation is
x=1.
The other way is to use the quadratic formula. The quadratic formula is given as [-b(+-)sqrt(b^2-4ac)]/2a where, using our sample equation above, a=1, b=2 and c=1. Substitute these to the formula, and you will get the same answer as the method above.
Because the order doesn't matter on where each person sits use the combinations formula:
C = n! / (r!(n-r)!)
Where n is the total number of people and r is the number of chairs.
C = 6! / (4!(6-4)!)
C = (6*5*4*3*2*1) / ((4*3*2*1(2*1))
C = 720 / (24*2)
C = 720 / 48
C = 15
There are 15 different arrangements.
Answer: a) 0.7
b) 70%
Step-by-step explanation:
a) There are 10 marbles.The red marbles are 7
so that 7/10
then change to decimal 7/10=0.7
b) if we get percentage *100
so, 7÷10*100%
70%
Answer:
A. & B.
Step-by-step explanation:
General form is ax2 + bx + c = 0.
Must contain an x2 term
Must NOT contain terms with degrees higher than x2 eg. x3, x4 etc
