Answer:
x = - 4
Step-by-step explanation:
Hi there !
if f(x) = 2x + 7 and f(x) = -1 =>
2x + 7 = - 1
2x = - 1 - 7
2x = - 8
x = - 8 ÷ 2
x = - 4
Good luck !
Both of these lines share the relationship together of being parallel.
0.3*42 this gives you a 30% discount
3/10*42 this gives you a 30% discount
0.03*42 this gives you a 3% discount
3 *4.2 This is not a discount
Okay, take a look at diagram 1 (I know it's rubbish I did it on paint :D), this shows all the information you've given in the question. The two coordinates and the distance between them.
Now if we draw additional lines on this diagram, we can make a right-angled triangle (this is on diagram 2). We can also work out the lengths of the additional sides because we know both coordinates at the end-points of the additional lines.
Finally because this is a right-angled triangle, Pythagoras' theorem must apply to its sides meaning



therefore x=5.