Question

Help us plazz this is mathematics IGCSE fast as you can​

Answer 1

Answer:

The value of y is 8.

Step-by-step explanation:

Given that y is directly proportional to √(x+5) so the equation is y = k√(x+5) where k is constant. First, you have to find the value of k with given values :

$y = k \sqrt{x + 5}$

$let \: x = - 1,y = 4$

$4 = k \sqrt{ - 1 + 5}$

$4 = k \sqrt{4}$

$4 = k(2)$

$4 \div 2 = k$

$k = 2$

So the equation is y = 2√(x+5). In order to find the value of y, you have to substitute x = 11 into the equation :

$y = 2 \sqrt{x + 5}$

$let \: x = 11$

$y = 2 \sqrt{11 + 5}$

$y = 2 \sqrt{16}$

$y = 2(4)$

$y = 8$

Answer 2

Answer:

Step-by-step explanation:

y varies direcrtly with √(x+5) wich can be expressed mathematically as:

● y = k*√(x+5)

Let's calculate k khowing that y=4 and x=-1

● 4 = k*√(-1+5)

● 4 = k*√(4)

● 4 = k * 2

● k = 4/2

● k = 2

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Let's calculate y khowing that x = 11

● y = k*√(x+5)

● y = 2×√(11+5)

● y = 2× √(16)

● y = 2× 4

● y = 8