Answer:
B
I hope this could help you ^^
Answer: the answer is
=3
−19x−14
Step-by-step explanation: (x−7)(3x+2)
=(x+−7)(3x+2)
=(x)(3x)+(x)(2)+(−7)(3x)+(−7)(2)
=3x2+2x−21x−14
=3x2−19x−14
Where is the rest of the question??
Answer:
72 kg
Step-by-step explanation:
For concreatting a tower cement, sand, stones are in the ratio 1:2:4 For 144kg sand.. What amount of cement is required?
We are given the ratio
cement: sand:stones
= 1:2:4
The sum of proportion =
1 + 2 + 4 = 7
We are given the kg of sand = 144kg
Step 1
We find the total kg of cement, sand and stones = x
Using the proportion of sand,
2/7 of x = 144kg
2/7 × x = 144kg
2x/7 = 144kg
Cross Multiply
2x = 7 × 144kg
x = 7 × 144kg/2
x = 504kg
Therefore the total kg of cement, sand and stone = 504kg
Step 2
The amount of cement required is calculated as:
1/7 × 504 kg = 72 kg
Therefore, 72kg of cement is required.
3x + 1 = y
2x + 3y = 14
To solve this system of equations, we are going to use the substitution method. Substitution the equation where the variable is isolated into the second equation. In this system of equations, y is isolated, so we will replace y in the second equation with 3x + 1.
2x + 3y = 14
2x + 3(3x + 1) = 14
2x + 9x + 3 = 14
We will add the like terms and subtract 3 from both sides of the equation.
11x + 3 = 14
11x = 11
x = 1
In this system of equations, x is equal to 1. Now we will go back and solve for y, plugging in 1 for x.
3(1) + 1 = y
2(1) + 3y = 14
3 + 1 = y
2 + 3y = 14
4 = y
3y = 2
4 = y
4 = y
The solution to this system of equations is (1, 4).
