Help me pleeeeeeeeeaze

Mathematics

1 answer:

kobusy [5.1K]2 years ago

5 0

$a(x+3) < 5x+15-x\\\\ax+3a < 5x+15-x\\\\ax+3a < 4x+15\ \ \ |-3a\\\\ax < 4x+15-3a\ \ \ \ |-4x\\\\ax-4x < 15-3a\\\\(a-4)x < 15-3a\\\\\text{The solution is all real numbers if}\ a-4=0\ \ \ |+4\\\\\boxed{a=4}\\\\\text{Check:}\\\\4(x+3) < 5x+15-x\\4x+12 < 4x+15\ \ \ \ |-4x\\12 < 15\ TRUE\to x\in\mathbb{R}$

You might be interested in

I don’t know how to find X or Y very urgent, need to figure this out how to solve plz help

Lena [83]

Answer:

x = 9

y = 9√3 = 15.6

Step-by-step explanation:

The triangle given is a right triangle, therefore:

✔️apply trigonometric ratio formula to find x:

Reference angle = 60°

Hypotenuse = 18

Adjacent = x

Thus:

Cos (60) = x/18

Multiply both sides by 18

18×cos(60) = x

9 = x

x = 9

✔️find y by applying pythagorean theorem:

y² = 18² - x² (pythagorean theorem)

y² = 18² - 9² (substitution)

y² = 243

y = √243

y = √(81*3)

y = 9√3 = 15.6

3 0

2 years ago

After drawing the line y = 2x − 1 and marking the point A = (−2, 7), Kendall is trying to decide which point on the line is clos

igor_vitrenko [27]

Answer:

Step-by-step explanation:

Having drawn the line, Kendall must verify that the point P belongs to the line y = 2x-1 and then calculate the distance between A-P and verify if it is the closest to A or there is another one of the line

Having the point P(3,5) substitue x to verify y

y=2*(3)-1=6-1=5 (3,5)

Now if the angle formed by A and P is 90º it means that it is the closest point, otherwise that point must be found

$d_{AP}=\sqrt{(y_{2}-y_{1})^{2}+(x_{2}-x_{1})^{2}}=\sqrt{(5-7)^{2}+(3-(-2}))^{2}}=\\\sqrt{(-2)^{2}+(5)^{2}}=\sqrt{29}$