Answer:
x+14y
Step-by-step explanation:
9x+2y-8x+12y
x+14y
Answer: the equations are
0.02x + 0.07y = 156
y = 300 + x
Step-by-step explanation:
Let x represent the total dollar amount of phone sales that she makes.
Let y represent the the total dollar amount of computer sales that she makes.
Josiah earns a 2% commission on the total dollar amount of all phone sales he makes, and earns a 7% commission on all computer sales. She earned a total of $156 in commission. This means that
0.02x + 0.07y = 156 - - - - - - - - - - -1
Josiah had $300 more in computer sales than in phone sales. This means that
y = 300 + x
Answer:
The numbers are 19 and 71.
Step-by-step explanation:
Let x and y represent the two numbers. Then x + y = 90.
Also, if we assume that the larger number is y, then y = 3x + 14.
We must solve this system of linear equations. Since we already have the result of solution for y (y = 3x + 14), let's use the substitution method to find the solution:
x + y = 90 becomes x + 3x + 14 = 90, or:
4x = 76. Thus, x = 76/4, or 19. If x = 19, then y = 3(19) + 14, or y = 71.
The numbers are 19 and 71.
Note that these add up to 90, as they must, and that 71 is 14 more than 3 times 19.
Answer:
k = 11.
Step-by-step explanation:
y = x^2 - 5x + k
dy/dx = 2x - 5 = the slope of the tangent to the curve
The slope of the normal = -1/(2x - 5)
The line 3y + x =25 is normal to the curve so finding its slope:
3y = 25 - x
y = -1/3 x + 25/3 <------- Slope is -1/3
So at the point of intersection with the curve, if the line is normal to the curve:
-1/3 = -1 / (2x - 5)
2x - 5 = 3 giving x = 4.
Substituting for x in y = x^2 - 5x + k:
When x = 4, y = (4)^2 - 5*4 + k
y = 16 - 20 + k
so y = k - 4.
From the equation y = -1/3 x + 25/3, at x = 4
y = (-1/3)*4 + 25/3 = 21/3 = 7.
So y = k - 4 = 7
k = 7 + 4 = 11.
