Answer:
Second option: 81y^4 - 16x^2, the difference of squares
Step-by-step explanation:
(9y^2-4x)(9y^2+4x) is a special product named difference of squares, then we can apply this formula:
(a-b)(a+b)=a^2-b^2, with a=9y^2 and b=4x, then:
(9y^2-4x)(9y^2+4x)=(9y^2)^2 - (4x)^2
(9y^2-4x)(9y^2+4x)=(9)^2 (y^2)^2 - (4)^2 (x)^2
(9y^2-4x)(9y^2+4x)=81y^(2*2) - 16x^2
(9y^2-4x)(9y^2+4x)=81y^4 - 16x^2
Answer:
3 litros
Step-by-step explanation:
Joana alugou um carro para fazer uma viagem de 36km sabendo que o carro percorre 12 km cm 1 litro custa
Da pergunta:
12 km = 1 litro
36km = x
Cross Multiply.
12x = 36 × 1
x = 36/12
x = 3 litros
<span>Multiply the number in the tens place of the bottom number by the number in hundreds place of the top number. Multiply 3 times 7 to equal 21. Add the 1 you carried to equal 22. You don't need to carry the 2 in 22, as there are no more numbers to multiply on this line, so you can just write it down next to the 6.</span>
Answer:
X=-0.6
Step-by-step explanation:
Hope it help
Packet of 12 pencils = p
Packet of 30 rulers = r
p = £2.15
r = £6.00
£35 = 4r + xp
£35 = 4(£6.00) + x(£2.15)
£35 = £24 + £2.15x
£11 = £2.15x
x = 5.12
Since she can buy 5.12 packets of pencils, it is equal to 5 packets of pencils.