Can anyone answer this GCSE cubic graph question??

Here is a question from Edexcel GCSE Maths mock exam Jan 2024:

On the grid draw the graph of y=x^3-3x+2 for values of x from -2 to 2

By drawing a suitable straight line on the grid, use your graph to find an estimate for the solution of
2x^3-3x+4=0

Give your answer correct to 1 decimal place

I rearranged equation 2 to give equation 1 on the left hand side, as follows:
x^3-3x+2=-x^3-2

I was expecting this to give a linear equation on the right hand side not a cubic

So plotting the graphs of y=x^3-3x+2 and y=-x^3-2 should give a solution to equation 2

And it does. These two graphs intersect at x=-1.6 which is roughly the solution to equation 2.

But y=-x^3-2 is not a straight line.

Any ideas what straight line they are after??

It’s GCSE so shouldn’t be too complex

Thanks

Boy do I feel like an idiot :-)

Yes of course that's the way to do it

For some reason I thought the 2x^3 was written in stone and unchangeable

Straight line y=-3x/2 gives intersect at x=-1.6

Thanks so much for your help mqb2766 and Anthony