X+12=-14? What’s the x? Plz help

Pick the expression that matches this description: a polynomial of the 5th degree with a leading coefficient of 7 and a constant term of 6 (choice a) 7x^5+2x^2+6 (choice b) 7x^6−6x^4+5 (choice c) 6x^7−x^5+5 (choice d) 6x^5+x^4+7

Anyone? 15m is what percent of 60m; 3m; 30m; 1.5 km?

Which coefficient matrix represents a system of linear equations that has a unique solution ? options in photo*