15% of 30....turn ur percent to a decimal...." of " means multiply
0.15(30) = 4.5
30% of 45.....set it up the same way as before
0.30(45) = 13.5
60% of 7
0.60(7) = 4.2
23% of 20
0.23(20) = 4.6
Using factorization method;
x²+13x+40=0
x²+13+40
Find two numbers that you can add together to give the co-efficient of variable x. (I.e 13 for this question). Also, you'll find two numbers that you can multiply with each other to give you the whole number as an answer. (I.e 40 in this question). The two numbers must be the same (i.e the two numbers that will be added to give the co-efficient of x and the two numbers that will be multiplied to give the whole number must be the same two).
The two numbers are +5 and +8
The equation will therefore be = x²+5x+8x+40
You'll then factorize (I.e use a common factor of both values to bracket them)
x(x+5)+8(x+5)
(x+8)(x+5)
x is therefore (x+8=0) or (x+5=0)
x=(x=0-8) or (x=0-5)
x= -8 or x= -5
The value of the element in row 1, column 1 of matrix x is; y.
<h3>What is the value of the element in row 1, column 1 of matrix x?</h3>
According to the task content, it follows that matrix x is defined as; x= [y 4].
In essence, it follows that the matrix x contains one row and 2 columns. Therefore, the element in row 1, column 1 of matrix x is; y.
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Answer:
(1, -5)
Step-by-step explanation:
Solve the system by setting the equations equal to each other, and solving for x:
-7x + 2 = 9x - 14
2 = 16x - 14
16 = 16x
1 = x
So, the x coordinate of the solution will be 1.
Plug in 1 as x into one of the equations, and solve for y
y = -7x + 2
y = -7(1) + 2
y = -7 + 2
y = -5
So, the y coordinate is -5.
The ordered pair solution is (1, -5)
Answer:
A salad costs $2.50
A sandwich costs $4.50
A drink costs $1.25
Step-by-step explanation:
Let x represent the salad, y represent the sandwich, and z represent the drink.
Since three salads, two sandwiches, and one drink cost $17.75:
3x + 2y + z = 17.75 (1)
Since one salad, one sandwich, and three drinks cost $10.75:
x + y + 3z = 10.75 (2)
Since a salad costs twice as much as a drink:
x = 2z (3)
Multiply the equation 2 by -2 then, sum the equation 1 and equation 2:
-2x - 2y - 6z = -21.50
3x + 2y + z = 17.75
→ x - 5z = -3.75
Replace the x with 2z using equation 3:
2z - 5z = -3.75
-3z = -3.75
z = 1.25
x = 2z → x = 2.50
x + y + 3z = 10.75 → 2.50 + y + 3.75 = 10.75 → y + 6.25 = 10.75 → y = 4.50
