• Expand (2a + b)²:
(2a + b)²
= (2a + b) · (2a + b)
Multiply out the brackets by applying the distributive property of multiplication:
= (2a + b) · 2a + (2a + b) · b
= 2a · 2a + b · 2a + 2a · b + b · b
= 2²a² + 2ab + 2ab + b²
Now, group like terms together, and you get
= 2²a² + 4ab + b²
= 4a² + 4ab + b² <——— expanded form (this is the answer).
I hope this helps. =)
Tags: <em>special product square of a sum algebra</em>
Answer: D ( 17/20)
Step-by-step explanation:
The two choices are:
The ‘standard’ tariff charges = $0.10 per unit
The ‘day/night tariff’ = $0.12 per unit for each unit consumed between 06:00 and 22:00 but only $0.05 for each unit consumed between 22:00 and 06:00
The day time is between 22:00 and 06:00
Time = 22 - 6 = 16 hours
Let assume that the charges are unit per hour.
For standard tariff = (16 × 0.10) + 0.2
Standard tariff = 1.6 + 0.2 = 1.8
For day/night = (16 × 0.12) + 0.2
= 1.92 + 0.2
= 2.12
The proportion will be
1.8/2.12 = 17/20 ( approximately)
Answer:
Step-by-step explanation:
4x + 3y = -1 --------------(i)
3x - 9y = 33 -------------(ii)
multiply equation (i) by 3
(i)* 3 12x + 9y = -3
(ii) <u> 3x - 9y = 33</u>
add, 15x = 30
x = 30/15
x = 2
Put x =2 in Equation (i)
4*2 + 3y = -1
8 +3y = -1
3y = -1-8
3y = -9
y = -9/3
y= -3
