Answer:
2. x = 2 & y = 4
3. x = 4 & y = 2
Step-by-step explanation:
2. x + y = 6
2x + y = 8 (multiply the first equation by -1, so you can eliminate the ys)
- x - y = -6
2x + y = 8 (now add the variables together)
x = 2 (plug in x in one of the equations to find out y)
x + y = 6
(2) + y = 6
-2 -2
y = 4
3. 3x + y = 14
x = 2y (plug in x into the first equation and solve it for y)
3(2y) + y = 14
6y + y = 14
7y = 14
y = 2 (plug in y in one of the equations to find out x)
x = 2y
x = 2(2)
x = 4
4. One number (x) is 2 more (+2) than twice (times 2) as large as another. their sum is 17. Find the numbers.
2x + 2 = 17 (solve for x)
-2 -2
2x = 15
x = 7.5
6. 7 (4x + 1) - (x + 6) (start by distributing 7 into the first parenthesis)
(28x + 7) - (x + 6) (do the same to the other parenthesis by distributing -1)
(28x + 7) (-x - 6) (and now just combine like terms)
28x + 7 - x - 6
28x - x + 7 - 6
27x + 1
i hope this helped! if you have any question, pls let me know!
Answer:
(5, 0 )
Step-by-step explanation:
Given the 2 equations
y = x² - 2x - 15 → (1)
y = 8x - 40 → (2)
Substitute y = x² - 2x - 15 into (2)
x² - 2x - 15 = 8x - 40 ( subtract 8x - 40 from both sides )
x² - 10x + 25 = 0 ← in standard form
(x - 5)² = 0 ← in factored form, thus
x - 5 = 0 ⇒ x = 5
Substitute x = 5 into (2) for corresponding value of y
y = 8(5) - 40 = 40 - 40 = 0
Solution is (5, 0 )
Answer and Step-by-step explanation:
1) 12*12 = 144
2) 2*2*2 = 8
Answer:
Ratio = 11:9
Boys = 440
Girls = 360
Explanation:
Given that, in a school,
Total number of students = 800
Also,
Percent of boys = 55%
Therefore, number of boys = 55% of 800
No. of boys = 55/100 x 800
No. of boys = 55 x 8 =
No. of boys = 440
Therefore, we will get,
No. of girls = (800-440)
No. of girls = 360
Therefore, we will get,
Ratio of boys to girls = 440/360
Ratio = (40*11)/(40x9)
Ratio = 11/9
Hence, the ratio of boys to girls is 11:9 and number of boys and girls is 440 and 360 respectively.
