Can someone please help me with my maths

a

Step-by-step explanation:

Recall that the "point-slope" form of a linear equation may be expressed as

y = mx + b,

where  m is the gradient.

If m is negative, the gradient is negative.

If m is positive, the gradient is positive.

In our case, if we consider option A,

x + 3y = -2  (rearranging)

3y = -x -2

y = (-1/3) x - (2/3)

if we compare this to the general equation at the top, we can see that

gradient, = m = (-1/3) which is negative.

hence option a has a negative gradient.

second option

step-by-step explanation:

the measures of a triangle equal 180. use that to find x.

2x+3x+4x=180

9x=180

9x/9=180/9

x=20

now you know x, you know angle a is 40°, angle b is 60°, angle c is 80°.

because angle a is 40°, the first option doesn't work.

because angle b is 60°, the second option does work.

when you add angle a and b, you get 100°. complementary means it equals 90°, so the third option doesn't work.

when you add angle a and c, you get 120°, which is not 100.

(5x-1)^2= (5x)^2-2(5x)×1+(1)^2=25x^2-10x+1