Answer:
Dan is 29. Cary is 36.
Step-by-step explanation:
Let Dan's age now be D.
Let Cary's age now be C.
"Cary is 7 years older than Dan."
C = D + 7
"In 7 years the sum of their ages will be 79. "
In 7 years, the ages of Dan and Cary will be D + 7 and C + 7, respectively.
D + 7 + C + 7 = 79
C + D + 14 = 79
C + D = 65
C = D + 7
The last two equations in bold above form a system of equations. Since the second equation is already solved for C, we use the substitution method.
D + 7 + D = 65
2D + 7 = 65
2D = 58
D = 29
C = D + 7
C = 29 + 7
C = 36
Answer: Dan is 29. Cary is 36.
Hello,
cos 160°=-q
cos 20°=-cos 160°=q
sin 20°=√(1-q²)=sin 160°
tan -20°=tan 160=√(1-q²)/-q
cos 70°=sin 20°=√(1-q²)
The sum means adding, so your answer is f + 6
What is the math problem?
Answer:
We have the equation:
(ax^2 + 3x + 2b) - (5x^2+bx-3c)= 3x^2 - 9
First, move all to the left side.
(ax^2 + 3x + 2b) - (5x^2+bx-3c) - 3x^2 + 9 = 0
Now let's group togheter terms with the same power of x.
(a - 5 - 3)*x^2 + (3 - b)*x + (2b + 3c + 9) = 0.
This must be zero for all the values of x, then the things inside each parenthesis must be zero.
1)
a - 5 - 3 = 0
a = 3 + 5 = 8.
2)
3 - b = 0
b = 3.
3)
2b + 3c + 9 = 0
2*3 + 3c + 9 = 0
3c = -6 - 9 = -15
c = -15/3 = -5
Then we have:
a = 8, b = 3, c = -5
a + b + c = 8 + 3 - 5 = 6
