7m - 3n
m = 3, n = 2
Replace m and n with the appropriate numbers:
7(3) - 3(2)
Multiply both sides:
21 - 6
Subtract:
21-6 = 15
Answer:
£1.80/kg
Step-by-step explanation:
The total spent on apples and pears is £12.70, and this is the sum of the costs of the apples and the pears respectively:
£12.70 = (unit cost of apples)(2 kg) + (unit cost of pears)(7 kg), or
£12.70 = (unit cost of apples)(2 kg) + (£1.30/kg)(7 kg).
Solving for (unit cost of apples)(2 kg), we get £12.70 - (£1.30/kg)(7 kg), or:
(unit cost of apples)(2 kg) = £12.70 - £9.1 = £3.60
Solving for (unit cost of apples), we divide both sides by (2 kg), obtaining:
£3.60
(unit cost of apples) = ---------- = £1.80/kg
2 kg
The quadratic formula is -b +/-sqrt(b^2-4ac) all over 2a.
First we have to get all the variables on one side so... Subtract 4x: 0=-4x^(2)+13x-3
OR add 3 and subtract 13x: 4x^(2)-13x+3=0
Since I prefer a to be positive, I'm going to choose the second equation.
So... now we just plug and chug. a is the value of the variable squared. In this case a=4. b is the value with the variable, or b=-13. c is the last term. c=3
**Remember: Ax^(2)+By+C**
Now we just plug everything in.
-b= 13 (negative minus a negative is a positive)
+/-sqrt((-13)^(2)-4(4)(3))
all over 2(4)
So work with the radical first.
(-13)^2=169
4(4)(3)=48
+/-sqrt(169-48)
+-sqrt(121)
sqrt(121)=11
Now it's just: (13+/-11)/2(4)
(13+/-11)/8
Split this into two equations:
(13+11)/8
(13-11)/8
Solve both: 24/8=3
2/8=1/4
So x= 3, 1/4
Plug them back in and see if there's one solution or two:
4(3)^2=13(3)-3
36=36
So x=3.
How about 1/4?:
4(1/4)^2=13(1/4)-3
4(1/16)=13/4-3
4/16=13/4-3
1/4=13/4-3
1/4=13/4-(3x4)/(1x4) *Like denominators to add or subtract*
1/4=13/4-12/4
1/4=1/4.
So x=1/4.
In this case, both answers work. So the answer, using the quadratic formula is x=1/4, x=3
Answer:
Alternate Interior Angles:
∠3 ≅ ∠5
Corresponding Angles:
∠3 ≅ ∠7
∠4 ≅ ∠8
Supplementary Angles:
∠3 is supplementary to ∠6
Step-by-step explanation: