Calculatingthe resultant gravitational force on spherical objects

[naushaan]

Homework Statement

Hi guys, I'm stuck on this homework question: Three uniform spheres of masses m1 = 2.50 kg, m2 = 4.00 kg, and m3 = 7.50 kg are placed at the corners of a right triangle (see figure below). Calculate the resultant gravitational force on the object of mass m2, assuming the spheres are isolated from the rest of the Universe. So I got the 'j' part correct, but for the 'i' part it's telling me the magnitude is correct but the direction is not. I'm confused as to what this means.

Relevant Equations

F=GMm/r^2

 

[kuruman]

It looks like the positive x-axis points to the right. The x-component of the force points to the left. So ...

 

[naushaan]

i forgot to make it a negative! thank you for your help